@misc{5415,
abstract = {Recently there has been a significant effort to add quantitative properties in formal verification and synthesis. While weighted automata over finite and infinite words provide a natural and flexible framework to express quantitative properties, perhaps surprisingly, several basic system properties such as average response time cannot be expressed with weighted automata. In this work, we introduce nested weighted automata as a new formalism for expressing important quantitative properties such as average response time. We establish an almost complete decidability picture for the basic decision problems for nested weighted automata, and illustrate its applicability in several domains. },
author = {Chatterjee, Krishnendu and Henzinger, Thomas A and Otop, Jan},
issn = {2664-1690},
pages = {27},
publisher = {IST Austria},
title = {{Nested weighted automata}},
doi = {10.15479/AT:IST-2014-170-v1-1},
year = {2014},
}
@misc{5421,
abstract = {Evolution occurs in populations of reproducing individuals. The structure of the population affects the outcome of the evolutionary process. Evolutionary graph theory is a powerful approach to study this phenomenon. There are two graphs. The interaction graph specifies who interacts with whom in the context of evolution. The replacement graph specifies who competes with whom for reproduction. The vertices of the two graphs are the same, and each vertex corresponds to an individual. A key quantity is the fixation probability of a new mutant. It is defined as the probability that a newly introduced mutant (on a single vertex) generates a lineage of offspring which eventually takes over the entire population of resident individuals. The basic computational questions are as follows: (i) the qualitative question asks whether the fixation probability is positive; and (ii) the quantitative approximation question asks for an approximation of the fixation probability. Our main results are: (1) We show that the qualitative question is NP-complete and the quantitative approximation question is #P-hard in the special case when the interaction and the replacement graphs coincide and even with the restriction that the resident individuals do not reproduce (which corresponds to an invading population taking over an empty structure). (2) We show that in general the qualitative question is PSPACE-complete and the quantitative approximation question is PSPACE-hard and can be solved in exponential time.},
author = {Chatterjee, Krishnendu and Ibsen-Jensen, Rasmus and Nowak, Martin},
issn = {2664-1690},
pages = {27},
publisher = {IST Austria},
title = {{The complexity of evolution on graphs}},
doi = {10.15479/AT:IST-2014-190-v2-2},
year = {2014},
}
@article{2257,
abstract = {Maximum entropy models are the least structured probability distributions that exactly reproduce a chosen set of statistics measured in an interacting network. Here we use this principle to construct probabilistic models which describe the correlated spiking activity of populations of up to 120 neurons in the salamander retina as it responds to natural movies. Already in groups as small as 10 neurons, interactions between spikes can no longer be regarded as small perturbations in an otherwise independent system; for 40 or more neurons pairwise interactions need to be supplemented by a global interaction that controls the distribution of synchrony in the population. Here we show that such “K-pairwise” models—being systematic extensions of the previously used pairwise Ising models—provide an excellent account of the data. We explore the properties of the neural vocabulary by: 1) estimating its entropy, which constrains the population's capacity to represent visual information; 2) classifying activity patterns into a small set of metastable collective modes; 3) showing that the neural codeword ensembles are extremely inhomogenous; 4) demonstrating that the state of individual neurons is highly predictable from the rest of the population, allowing the capacity for error correction.},
author = {Tkacik, Gasper and Marre, Olivier and Amodei, Dario and Schneidman, Elad and Bialek, William and Berry, Michael},
issn = {1553734X},
journal = {PLoS Computational Biology},
number = {1},
publisher = {Public Library of Science},
title = {{Searching for collective behavior in a large network of sensory neurons}},
doi = {10.1371/journal.pcbi.1003408},
volume = {10},
year = {2014},
}
@article{5813,
abstract = {We consider homogeneous Bose gas in a large cubic box with periodic boundary conditions, at zero temperature. We analyze its excitation spectrum in a certain kind of a mean-field infinite-volume limit. We prove that under appropriate conditions the excitation spectrum has the form predicted by the Bogoliubov approximation. Our result can be viewed as an extension of the result of Seiringer (Commun. Math. Phys.306:565–578, 2011) to large volumes.},
author = {Dereziński, Jan and Napiórkowski, Marcin M},
issn = {1424-0637},
journal = {Annales Henri Poincaré},
number = {12},
pages = {2409--2439},
publisher = {Springer Nature},
title = {{Excitation spectrum of interacting bosons in the Mean-Field Infinite-Volume limit}},
doi = {10.1007/s00023-013-0302-4},
volume = {15},
year = {2014},
}
@article{589,
abstract = {We demonstrate a many-atom-cavity system with a high-finesse dual-wavelength standing wave cavity in which all participating rubidium atoms are nearly identically coupled to a 780-nm cavity mode. This homogeneous coupling is enforced by a one-dimensional optical lattice formed by the field of a 1560-nm cavity mode.},
author = {Lee, Jongmin and Vrijsen, Geert and Teper, Igor and Onur Hosten and Kasevich, Mark A},
journal = {Optics Letters},
number = {13},
pages = {4005 -- 4008},
publisher = {OSA},
title = {{Many-atom-cavity QED system with homogeneous atom-cavity coupling}},
doi = {10.1364/OL.39.004005},
volume = {39},
year = {2014},
}
@article{6122,
author = {Linneweber, Gerit A. and Jacobson, Jake and Busch, Karl Emanuel and Hudry, Bruno and Christov, Christo P. and Dormann, Dirk and Yuan, Michaela and Otani, Tomoki and Knust, Elisabeth and de Bono, Mario and Miguel-Aliaga, Irene},
issn = {0092-8674},
journal = {Cell},
number = {1-2},
pages = {69--83},
publisher = {Elsevier},
title = {{Neuronal control of metabolism through nutrient-dependent modulation of tracheal branching}},
doi = {10.1016/j.cell.2013.12.008},
volume = {156},
year = {2014},
}
@article{6124,
abstract = {Despite the importance of G-protein coupled receptors (GPCRs) their biogenesis is poorly understood. Like vertebrates, C. elegans uses a large family of GPCRs as chemoreceptors. A subset of these receptors, such as ODR-10, requires the odr-4 and odr-8 genes to be appropriately localized to sensory cilia. The odr-4 gene encodes a conserved tail-anchored transmembrane protein; the molecular identity of odr-8 is unknown. Here, we show that odr-8 encodes the C. elegans ortholog of Ufm1-specific protease 2 (UfSP2). UfSPs are cysteine proteases identified biochemically by their ability to liberate the ubiquitin-like modifier Ufm1 from its pro-form and protein conjugates. ODR-8/UfSP2 and ODR-4 are expressed in the same set of twelve chemosensory neurons, and physically interact at the ER membrane. ODR-4 also binds ODR-10, suggesting that an ODR-4/ODR-8 complex promotes GPCR folding, maturation, or export from the ER. The physical interaction between human ODR4 and UfSP2 suggests that this complex's role in GPCR biogenesis may be evolutionarily conserved. Unexpectedly, mutant versions of ODR-8/UfSP2 lacking catalytic residues required for protease activity can rescue all odr-8 mutant phenotypes tested. Moreover, deleting C. elegans ufm-1 does not alter chemoreceptor traffic to cilia, either in wild type or in odr-8 mutants. Thus, UfSP2 proteins have protease- and Ufm1-independent functions in GPCR biogenesis.},
author = {Chen, Changchun and Itakura, Eisuke and Weber, Katherine P. and Hegde, Ramanujan S. and de Bono, Mario},
issn = {1553-7404},
journal = {PLoS Genetics},
number = {3},
publisher = {Public Library of Science (PLoS)},
title = {{An ER complex of ODR-4 and ODR-8/Ufm1 specific protease 2 promotes GPCR maturation by a Ufm1-independent mechanism}},
doi = {10.1371/journal.pgen.1004082},
volume = {10},
year = {2014},
}
@article{6126,
abstract = {Aerobic animals constantly monitor and adapt to changes in O2 levels. The molecular mechanisms involved in sensing O2 are, however, incompletely understood. Previous studies showed that a hexacoordinated globin called GLB-5 tunes the dynamic range of O2-sensing neurons in natural C. elegans isolates, but is defective in the N2 lab reference strain (McGrath et al., 2009; Persson et al., 2009). GLB-5 enables a sharp behavioral switch when O2 changes between 21 and 17%. Here, we show that GLB-5 also confers rapid behavioral and cellular recovery from exposure to hypoxia. Hypoxia reconfigures O2-evoked Ca2+ responses in the URX O2 sensors, and GLB-5 enables rapid recovery of these responses upon re-oxygenation. Forward genetic screens indicate that GLB-5's effects on O2 sensing require PDL-1, the C. elegans ortholog of mammalian PrBP/PDE6δ protein. In mammals, PDE6δ regulates the traffic and activity of prenylated proteins (Zhang et al., 2004; Norton et al., 2005). PDL-1 promotes localization of GCY-33 and GCY-35, atypical soluble guanylate cyclases that act as O2 sensors, to the dendritic endings of URX and BAG neurons, where they colocalize with GLB-5. Both GCY-33 and GCY-35 are predicted to be prenylated. Dendritic localization is not essential for GCY-35 to function as an O2 sensor, but disrupting pdl-1 alters the URX neuron's O2 response properties. Functional GLB-5 can restore dendritic localization of GCY-33 in pdl-1 mutants, suggesting GCY-33 and GLB-5 are in a complex. Our data suggest GLB-5 and the soluble guanylate cyclases operate in close proximity to sculpt O2 responses.},
author = {Gross, E. and Soltesz, Z. and Oda, S. and Zelmanovich, V. and Abergel, Z. and de Bono, Mario},
issn = {0270-6474},
journal = {Journal of Neuroscience},
number = {50},
pages = {16726--16738},
publisher = {Society for Neuroscience},
title = {{GLOBIN-5-dependent O2 responses are regulated by PDL-1/PrBP that targets prenylated soluble guanylate cyclases to dendritic endings}},
doi = {10.1523/jneurosci.5368-13.2014},
volume = {34},
year = {2014},
}
@article{6319,
abstract = {Nous étudions le comportement asymptotique du nombre de variétés dans une certaine classe ne satisfaisant pas le principe de Hasse. Cette étude repose sur des résultats récemmentobtenus par Colliot-Thélène.},
author = {Bretèche, Régis de la and Browning, Timothy D},
issn = {1246-7405},
journal = {Journal de Théorie des Nombres de Bordeaux},
number = {1},
pages = {25--44},
publisher = {Cellule MathDoc/CEDRAM},
title = {{Contre-exemples au principe de Hasse pour certains tores coflasques}},
doi = {10.5802/jtnb.857},
volume = {26},
year = {2014},
}
@article{6739,
abstract = {We explore the relationship between polar and RM codes and we describe a coding scheme which improves upon the performance of the standard polar code at practical block lengths. Our starting point is the experimental observation that RM codes have a smaller error probability than polar codes under MAP decoding. This motivates us to introduce a family of codes that “interpolates” between RM and polar codes, call this family C inter = {C α : α ∈ [0, 1j}, where C α|α=1 is the original polar code, and C α|α=0 is an RM code. Based on numerical observations, we remark that the error probability under MAP decoding is an increasing function of α. MAP decoding has in general exponential complexity, but empirically the performance of polar codes at finite block lengths is boosted by moving along the family Cinter even under low-complexity decoding schemes such as, for instance, belief propagation or successive cancellation list decoder. We demonstrate the performance gain via numerical simulations for transmission over the erasure channel as well as the Gaussian channel.},
author = {Mondelli, Marco and Hassani, Hamed and Urbanke, Rudiger},
issn = {0090-6778},
journal = {IEEE Transactions on Communications},
number = {9},
pages = {3084--3091},
publisher = {IEEE},
title = {{From polar to Reed-Muller codes: A technique to improve the finite-length performance}},
doi = {10.1109/tcomm.2014.2345069},
volume = {62},
year = {2014},
}
@inproceedings{6740,
abstract = {We describe coding techniques that achieve the capacity of a discrete memoryless asymmetric channel. To do so, we discuss how recent advances in coding for symmetric channels yield more efficient solutions also for the asymmetric case. In more detail, we consider three basic approaches. The first one is Gallager's scheme that concatenates a linear code with a non-linear mapper, in order to bias the input distribution. We explicitly show that both polar codes and spatially coupled codes can be employed in this scenario. Further, we derive a scaling law between the gap to capacity, the cardinality of channel input and output alphabets, and the required size of the mapper. The second one is an integrated approach in which the coding scheme is used both for source coding, in order to create codewords with the capacity-achieving distribution, and for channel coding, in order to provide error protection. Such a technique has been recently introduced by Honda and Yamamoto in the context of polar codes, and we show how to apply it also to the design of sparse graph codes. The third approach is based on an idea due to Böcherer and Mathar and separates completely the two tasks of source coding and channel coding by “chaining” together several codewords. We prove that we can combine any suitable source code with any suitable channel code in order to provide optimal schemes for asymmetric channels. In particular, polar codes and spatially coupled codes fulfill the required conditions.},
author = {Mondelli, Marco and Urbanke, Rudiger and Hassani, Hamed},
booktitle = {52nd Annual Allerton Conference on Communication, Control, and Computing},
location = {Monticello, IL, United States},
pages = {789--796},
publisher = {IEEE},
title = {{How to achieve the capacity of asymmetric channels}},
doi = {10.1109/allerton.2014.7028535},
year = {2014},
}
@article{7071,
abstract = {Spin and orbital quantum numbers play a key role in the physics of Mott insulators, but in most systems they are connected only indirectly—via the Pauli exclusion principle and the Coulomb interaction. Iridium-based oxides (iridates) introduce strong spin–orbit coupling directly, such that these numbers become entwined together and the Mott physics attains a strong orbital character. In the layered honeycomb iridates this is thought to generate highly spin–anisotropic magnetic interactions, coupling the spin to a given spatial direction of exchange and leading to strongly frustrated magnetism. Here we report a new iridate structure that has the same local connectivity as the layered honeycomb and exhibits striking evidence for highly spin–anisotropic exchange. The basic structural units of this material suggest that a new family of three-dimensional structures could exist, the ‘harmonic honeycomb’ iridates, of which the present compound is the first example.},
author = {Modic, Kimberly A and Smidt, Tess E. and Kimchi, Itamar and Breznay, Nicholas P. and Biffin, Alun and Choi, Sungkyun and Johnson, Roger D. and Coldea, Radu and Watkins-Curry, Pilanda and McCandless, Gregory T. and Chan, Julia Y. and Gandara, Felipe and Islam, Z. and Vishwanath, Ashvin and Shekhter, Arkady and McDonald, Ross D. and Analytis, James G.},
issn = {2041-1723},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
title = {{Realization of a three-dimensional spin–anisotropic harmonic honeycomb iridate}},
doi = {10.1038/ncomms5203},
volume = {5},
year = {2014},
}
@techreport{7038,
author = {Huszár, Kristóf and Rolinek, Michal},
pages = {5},
publisher = {IST Austria},
title = {{Playful Math - An introduction to mathematical games}},
year = {2014},
}
@inproceedings{772,
abstract = {Lock-free concurrent algorithms guarantee that some concurrent operation will always make progress in a finite number of steps. Yet programmers prefer to treat concurrent code as if it were wait-free, guaranteeing that all operations always make progress. Unfortunately, designing wait-free algorithms is generally a very complex task, and the resulting algorithms are not always efficient. While obtaining efficient wait-free algorithms has been a long-time goal for the theory community, most non-blocking commercial code is only lock-free. This paper suggests a simple solution to this problem. We show that, for a large class of lock-free algorithms, under scheduling conditions which approximate those found in commercial hardware architectures, lock-free algorithms behave as if they are wait-free. In other words, programmers can keep on designing simple lock-free algorithms instead of complex wait-free ones, and in practice, they will get wait-free progress. Our main contribution is a new way of analyzing a general class of lock-free algorithms under a stochastic scheduler. Our analysis relates the individual performance of processes with the global performance of the system using Markov chain lifting between a complex per-process chain and a simpler system progress chain. We show that lock-free algorithms are not only wait-free with probability 1, but that in fact a general subset of lock-free algorithms can be closely bounded in terms of the average number of steps required until an operation completes. To the best of our knowledge, this is the first attempt to analyze progress conditions, typically stated in relation to a worst case adversary, in a stochastic model capturing their expected asymptotic behavior.},
author = {Alistarh, Dan-Adrian and Censor Hillel, Keren and Shavit, Nir},
pages = {714 -- 723},
publisher = {ACM},
title = {{Are lock-free concurrent algorithms practically wait-free?}},
doi = {10.1145/2591796.2591836},
year = {2014},
}
@inproceedings{775,
abstract = {The long-lived renaming problem appears in shared-memory systems where a set of threads need to register and deregister frequently from the computation, while concurrent operations scan the set of currently registered threads. Instances of this problem show up in concurrent implementations of transactional memory, flat combining, thread barriers, and memory reclamation schemes for lock-free data structures. In this paper, we analyze a randomized solution for long-lived renaming. The algorithmic technique we consider, called the Level Array, has previously been used for hashing and one-shot (single-use) renaming. Our main contribution is to prove that, in long-lived executions, where processes may register and deregister polynomially many times, the technique guarantees constant steps on average and O (log log n) steps with high probability for registering, unit cost for deregistering, and O (n) steps for collect queries, where n is an upper bound on the number of processes that may be active at any point in time. We also show that the algorithm has the surprising property that it is self-healing: under reasonable assumptions on the schedule, operations running while the data structure is in a degraded state implicitly help the data structure re-balance itself. This subtle mechanism obviates the need for expensive periodic rebuilding procedures. Our benchmarks validate this approach, showing that, for typical use parameters, the average number of steps a process takes to register is less than two and the worst-case number of steps is bounded by six, even in executions with billions of operations. We contrast this with other randomized implementations, whose worst-case behavior we show to be unreliable, and with deterministic implementations, whose cost is linear in n.},
author = {Alistarh, Dan-Adrian and Kopinsky, Justin and Matveev, Alexander and Shavit, Nir},
pages = {348 -- 357},
publisher = {IEEE},
title = {{The levelarray: A fast, practical long-lived renaming algorithm}},
doi = {10.1109/ICDCS.2014.43},
year = {2014},
}
@article{7771,
abstract = {In their Letter, Schreck, Bertrand, O'Hern and Shattuck [Phys. Rev. Lett. 107, 078301 (2011)] study nonlinearities in jammed particulate systems that arise when contacts are altered. They conclude that there is "no harmonic regime in the large system limit for all compressions" and "at jamming onset for any system size." Their argument rests on the claim that for finite-range repulsive potentials, of the form used in studies of jamming, the breaking or forming of a single contact is sufficient to destroy the linear regime. We dispute these conclusions and argue that linear response is both justified and essential for understanding the nature of the jammed solid. },
author = {Goodrich, Carl Peter and Liu, Andrea J. and Nagel, Sidney R.},
issn = {0031-9007},
journal = {Physical Review Letters},
number = {4},
publisher = {American Physical Society},
title = {{Comment on “Repulsive contact interactions make jammed particulate systems inherently nonharmonic”}},
doi = {10.1103/physrevlett.112.049801},
volume = {112},
year = {2014},
}
@inproceedings{8044,
abstract = {Many questions concerning models in quantum mechanics require a detailed analysis of the spectrum of the corresponding Hamiltonian, a linear operator on a suitable Hilbert space. Of particular relevance for an understanding of the low-temperature properties of a system is the structure of the excitation spectrum, which is the part of the spectrum close to the spectral bottom. We present recent progress on this question for bosonic many-body quantum systems with weak two-body interactions. Such system are currently of great interest, due to their experimental realization in ultra-cold atomic gases. We investigate the accuracy of the Bogoliubov approximations, which predicts that the low-energy spectrum is made up of sums of elementary excitations, with linear dispersion law at low momentum. The latter property is crucial for the superfluid behavior the system.},
author = {Seiringer, Robert},
booktitle = {Proceeding of the International Congress of Mathematicans},
isbn = {9788961058063},
location = {Seoul, South Korea},
pages = {1175--1194},
publisher = {Kyung Moon SA},
title = {{Structure of the excitation spectrum for many-body quantum systems}},
volume = {3},
year = {2014},
}
@inproceedings{2082,
abstract = {NMAC is a mode of operation which turns a fixed input-length keyed hash function f into a variable input-length function. A practical single-key variant of NMAC called HMAC is a very popular and widely deployed message authentication code (MAC). Security proofs and attacks for NMAC can typically be lifted to HMAC. NMAC was introduced by Bellare, Canetti and Krawczyk [Crypto'96], who proved it to be a secure pseudorandom function (PRF), and thus also a MAC, assuming that (1) f is a PRF and (2) the function we get when cascading f is weakly collision-resistant. Unfortunately, HMAC is typically instantiated with cryptographic hash functions like MD5 or SHA-1 for which (2) has been found to be wrong. To restore the provable guarantees for NMAC, Bellare [Crypto'06] showed its security based solely on the assumption that f is a PRF, albeit via a non-uniform reduction. - Our first contribution is a simpler and uniform proof for this fact: If f is an ε-secure PRF (against q queries) and a δ-non-adaptively secure PRF (against q queries), then NMAC f is an (ε+ℓqδ)-secure PRF against q queries of length at most ℓ blocks each. - We then show that this ε+ℓqδ bound is basically tight. For the most interesting case where ℓqδ ≥ ε we prove this by constructing an f for which an attack with advantage ℓqδ exists. This also violates the bound O(ℓε) on the PRF-security of NMAC recently claimed by Koblitz and Menezes. - Finally, we analyze the PRF-security of a modification of NMAC called NI [An and Bellare, Crypto'99] that differs mainly by using a compression function with an additional keying input. This avoids the constant rekeying on multi-block messages in NMAC and allows for a security proof starting by the standard switch from a PRF to a random function, followed by an information-theoretic analysis. We carry out such an analysis, obtaining a tight ℓq2/2 c bound for this step, improving over the trivial bound of ℓ2q2/2c. The proof borrows combinatorial techniques originally developed for proving the security of CBC-MAC [Bellare et al., Crypto'05].},
author = {Gazi, Peter and Pietrzak, Krzysztof Z and Rybar, Michal},
editor = {Garay, Juan and Gennaro, Rosario},
location = {Santa Barbara, USA},
number = {1},
pages = {113 -- 130},
publisher = {Springer},
title = {{The exact PRF-security of NMAC and HMAC}},
doi = {10.1007/978-3-662-44371-2_7},
volume = {8616},
year = {2014},
}
@article{96,
abstract = {Multielectron spin qubits are demonstrated, and performance examined by comparing coherent exchange oscillations in coupled single-electron and multielectron quantum dots, measured in the same device. Fast (>1 GHz) exchange oscillations with a quality factor Q∼15 are found for the multielectron case, compared to Q∼2 for the single-electron case, the latter consistent with experiments in the literature. A model of dephasing that includes voltage and hyperfine noise is developed that is in good agreement with both single- and multielectron data, though in both cases additional exchange-independent dephasing is needed to obtain quantitative agreement across a broad parameter range.},
author = {Higginbotham, Andrew P and Kuemmeth, Ferdinand and Hanson, Micah and Gossard, Arthur and Marcus, Charles},
journal = {APS Physics, Physical Review Letters},
number = {2},
publisher = {American Physiological Society},
title = {{Coherent operations and screening in multielectron spin qubits}},
doi = {10.1103/PhysRevLett.112.026801},
volume = {112},
year = {2014},
}
@article{97,
abstract = {The distribution of Coulomb blockade peak heights as a function of magnetic field is investigated experimentally in a Ge-Si nanowire quantum dot. Strong spin-orbit coupling in this hole-gas system leads to antilocalization of Coulomb blockade peaks, consistent with theory. In particular, the peak height distribution has its maximum away from zero at zero magnetic field, with an average that decreases with increasing field. Magnetoconductance in the open-wire regime places a bound on the spin-orbit length (lso < 20 nm), consistent with values extracted in the Coulomb blockade regime (lso < 25 nm).},
author = {Higginbotham, Andrew P and Kuemmeth, Ferdinand and Larsen, Thorvald and Fitzpatrick, Mattias and Yao, Jun and Yan, Hao and Lieber, Charles and Marcus, Charles},
journal = {APS Physics, Physical Review Letters},
number = {21},
publisher = {American Physical Society},
title = {{Antilocalization of coulomb blockade in a Ge/Si nanowire}},
doi = {10.1103/PhysRevLett.112.216806},
volume = {112},
year = {2014},
}
@article{977,
abstract = {We propose a method for detecting many-body localization (MBL) in disordered spin systems. The method involves pulsed coherent spin manipulations that probe the dephasing of a given spin due to its entanglement with a set of distant spins. It allows one to distinguish the MBL phase from a noninteracting localized phase and a delocalized phase. In particular, we show that for a properly chosen pulse sequence the MBL phase exhibits a characteristic power-law decay reflecting its slow growth of entanglement. We find that this power-law decay is robust with respect to thermal and disorder averaging, provide numerical simulations supporting our results, and discuss possible experimental realizations in solid-state and cold-atom systems.},
author = {Maksym Serbyn and Knap, Michael J and Gopalakrishnan, Sarang and Papić, Zlatko and Yao, Norman Y and Laumann, Chris R and Abanin, Dmitry A and Lukin, Mikhail D and Demler, Eugene A},
journal = {Physical Review Letters},
number = {14},
publisher = {American Physical Society},
title = {{Interferometric probes of many-body localization}},
doi = {10.1103/PhysRevLett.113.147204},
volume = {113},
year = {2014},
}
@article{978,
abstract = {The newly discovered topological crystalline insulators feature a complex band structure involving multiple Dirac cones, and are potentially highly tunable by external electric field, temperature or strain. Theoretically, it has been predicted that the various Dirac cones, which are offset in energy and momentum, might harbour vastly different orbital character. However, their orbital texture, which is of immense importance in determining a variety of a materialâ €™ s properties remains elusive. Here, we unveil the orbital texture of Pb 1â ̂'x Sn x Se, a prototypical topological crystalline insulator. By using Fourier-transform scanning tunnelling spectroscopy we measure the interference patterns produced by the scattering of surface-state electrons. We discover that the intensity and energy dependences of the Fourier transforms show distinct characteristics, which can be directly attributed to orbital effects. Our experiments reveal a complex band topology involving two Lifshitz transitions and establish the orbital nature of the Dirac bands, which could provide an alternative pathway towards future quantum applications.},
author = {Zeljkovic, Ilija and Okada, Yoshinori and Huang, Chengyi and Sankar, Raman and Walkup, Daniel and Zhou, Wenwen and Maksym Serbyn and Chou, Fangcheng and Tsai, Wei-Feng and Lin, Hsin and Bansil, Arun and Fu, Liang and Hasan, Md Z and Madhavan, Vidya},
journal = {Nature Physics},
number = {8},
pages = {572 -- 577},
publisher = {Nature Publishing Group},
title = {{Mapping the unconventional orbital texture in topological crystalline insulators}},
doi = {10.1038/nphys3012},
volume = {10},
year = {2014},
}
@article{979,
abstract = {In the recently discovered topological crystalline insulators SnTe and Pb1-xSnx(Te, Se), crystal symmetry and electronic topology intertwine to create topological surface states with many interesting features including Lifshitz transition, Van-Hove singularity, and fermion mass generation. These surface states are protected by mirror symmetry with respect to the (110) plane. In this work we present a comprehensive study of the effects of different mirror-symmetry-breaking perturbations on the (001) surface band structure. Pristine (001) surface states have four branches of Dirac fermions at low energy. We show that ferroelectric-type structural distortion generates a mass and gaps out some or all of these Dirac points, while strain shifts Dirac points in the Brillouin zone. An in-plane magnetic field leaves the surface state gapless, but introduces asymmetry between Dirac points. Finally, an out-of-plane magnetic field leads to discrete Landau levels. We show that the Landau level spectrum has an unusual pattern of degeneracy and interesting features due to the unique underlying band structure. This suggests that Landau level spectroscopy can detect and distinguish between different mechanisms of symmetry breaking in topological crystalline insulators.},
author = {Maksym Serbyn and Fu, Liang},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {3},
publisher = {American Physical Society},
title = {{Symmetry breaking and Landau quantization in topological crystalline insulators}},
doi = {10.1103/PhysRevB.90.035402},
volume = {90},
year = {2014},
}
@article{98,
abstract = {Relaxation and dephasing of hole spins are measured in a gate-defined Ge/Si nanowire double quantum dot using a fast pulsed-gate method and dispersive readout. An inhomogeneous dephasing time T2* ∼ 0.18 μs exceeds corresponding measurements in III-V semiconductors by more than an order of magnitude, as expected for predominately nuclear-spin-free materials. Dephasing is observed to be exponential in time, indicating the presence of a broadband noise source, rather than Gaussian, previously seen in systems with nuclear-spin-dominated dephasing.},
author = {Higginbotham, Andrew P and Larsen, Thorvald and Yao, Jun and Yan, Hao and Lieber, Charles and Marcus, Charles and Kuemmeth, Ferdinand},
journal = {Nano Letters},
number = {6},
pages = {3582 -- 3586},
publisher = {American Chemical Society},
title = {{Hole spin coherence in a Ge/Si heterostructure nanowire}},
doi = {10.1021/nl501242b},
volume = {14},
year = {2014},
}
@article{980,
abstract = {Many-body localized (MBL) systems are characterized by the absence of transport and thermalization and, therefore, cannot be described by conventional statistical mechanics. In this paper, using analytic arguments and numerical simulations, we study the behavior of local observables in an isolated MBL system following a quantum quench. For the case of a global quench, we find that the local observables reach stationary, highly nonthermal values at long times as a result of slow dephasing characteristic of the MBL phase. These stationary values retain the local memory of the initial state due to the existence of local integrals of motion in the MBL phase. The temporal fluctuations around stationary values exhibit universal power-law decay in time, with an exponent set by the localization length and the diagonal entropy of the initial state. Such a power-law decay holds for any local observable and is related to the logarithmic in time growth of entanglement in the MBL phase. This behavior distinguishes the MBL phase from both the Anderson insulator (where no stationary state is reached) and from the ergodic phase (where relaxation is expected to be exponential). For the case of a local quench, we also find a power-law approach of local observables to their stationary values when the system is prepared in a mixed state. Quench protocols considered in this paper can be naturally implemented in systems of ultracold atoms in disordered optical lattices, and the behavior of local observables provides a direct experimental signature of many-body localization.},
author = {Maksym Serbyn and Papić, Zlatko and Abanin, Dmitry A},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {17},
publisher = {American Physical Society},
title = {{Quantum quenches in the many-body localized phase}},
doi = {10.1103/PhysRevB.90.174302},
volume = {90},
year = {2014},
}
@article{1912,
abstract = {Kupffer's vesicle (KV) is the zebrafish organ of laterality, patterning the embryo along its left-right (LR) axis. Regional differences in cell shape within the lumen-lining KV epithelium are essential for its LR patterning function. However, the processes by which KV cells acquire their characteristic shapes are largely unknown. Here, we show that the notochord induces regional differences in cell shape within KV by triggering extracellular matrix (ECM) accumulation adjacent to anterior-dorsal (AD) regions of KV. This localized ECM deposition restricts apical expansion of lumen-lining epithelial cells in AD regions of KV during lumen growth. Our study provides mechanistic insight into the processes by which KV translates global embryonic patterning into regional cell shape differences required for its LR symmetry-breaking function.},
author = {Compagnon, Julien and Barone, Vanessa and Rajshekar, Srivarsha and Kottmeier, Rita and Pranjic-Ferscha, Kornelija and Behrndt, Martin and Heisenberg, Carl-Philipp J},
journal = {Developmental Cell},
number = {6},
pages = {774 -- 783},
publisher = {Cell Press},
title = {{The notochord breaks bilateral symmetry by controlling cell shapes in the Zebrafish laterality organ}},
doi = {10.1016/j.devcel.2014.11.003},
volume = {31},
year = {2014},
}
@article{7598,
author = {Tan, Shutang and Xue, Hong-Wei},
issn = {2211-1247},
journal = {Cell Reports},
number = {5},
pages = {1692--1702},
publisher = {Elsevier},
title = {{Casein kinase 1 regulates ethylene synthesis by phosphorylating and promoting the turnover of ACS5}},
doi = {10.1016/j.celrep.2014.10.047},
volume = {9},
year = {2014},
}
@article{8021,
abstract = {Most excitatory inputs in the mammalian brain are made on dendritic spines, rather than on dendritic shafts. Spines compartmentalize calcium, and this biochemical isolation can underlie input-specific synaptic plasticity, providing a raison d'etre for spines. However, recent results indicate that the spine can experience a membrane potential different from that in the parent dendrite, as though the spine neck electrically isolated the spine. Here we use two-photon calcium imaging of mouse neocortical pyramidal neurons to analyze the correlation between the morphologies of spines activated under minimal synaptic stimulation and the excitatory postsynaptic potentials they generate. We find that excitatory postsynaptic potential amplitudes are inversely correlated with spine neck lengths. Furthermore, a spike timing-dependent plasticity protocol, in which two-photon glutamate uncaging over a spine is paired with postsynaptic spikes, produces rapid shrinkage of the spine neck and concomitant increases in the amplitude of the evoked spine potentials. Using numerical simulations, we explore the parameter regimes for the spine neck resistance and synaptic conductance changes necessary to explain our observations. Our data, directly correlating synaptic and morphological plasticity, imply that long-necked spines have small or negligible somatic voltage contributions, but that, upon synaptic stimulation paired with postsynaptic activity, they can shorten their necks and increase synaptic efficacy, thus changing the input/output gain of pyramidal neurons. },
author = {Araya, R. and Vogels, Tim P and Yuste, R.},
issn = {1091-6490},
journal = {Proceedings of the National Academy of Sciences},
number = {28},
pages = {E2895--E2904},
publisher = {Proceedings of the National Academy of Sciences},
title = {{Activity-dependent dendritic spine neck changes are correlated with synaptic strength}},
doi = {10.1073/pnas.1321869111},
volume = {111},
year = {2014},
}
@article{8022,
abstract = {Populations of neurons in motor cortex engage in complex transient dynamics of large amplitude during the execution of limb movements. Traditional network models with stochastically assigned synapses cannot reproduce this behavior. Here we introduce a class of cortical architectures with strong and random excitatory recurrence that is stabilized by intricate, fine-tuned inhibition, optimized from a control theory perspective. Such networks transiently amplify specific activity states and can be used to reliably execute multidimensional movement patterns. Similar to the experimental observations, these transients must be preceded by a steady-state initialization phase from which the network relaxes back into the background state by way of complex internal dynamics. In our networks, excitation and inhibition are as tightly balanced as recently reported in experiments across several brain areas, suggesting inhibitory control of complex excitatory recurrence as a generic organizational principle in cortex.},
author = {Hennequin, Guillaume and Vogels, Tim P and Gerstner, Wulfram},
issn = {0896-6273},
journal = {Neuron},
number = {6},
pages = {1394--1406},
publisher = {Elsevier},
title = {{Optimal control of transient dynamics in balanced networks supports generation of complex movements}},
doi = {10.1016/j.neuron.2014.04.045},
volume = {82},
year = {2014},
}
@article{8023,
abstract = {Uniform random sparse network architectures are ubiquitous in computational neuroscience, but the implicit hypothesis that they are a good representation of real neuronal networks has been met with skepticism. Here we used two experimental data sets, a study of triplet connectivity statistics and a data set measuring neuronal responses to channelrhodopsin stimuli, to evaluate the fidelity of thousands of model networks. Network architectures comprised three neuron types (excitatory, fast spiking, and nonfast spiking inhibitory) and were created from a set of rules that govern the statistics of the resulting connection types. In a high-dimensional parameter scan, we varied the degree distributions (i.e., how many cells each neuron connects with) and the synaptic weight correlations of synapses from or onto the same neuron. These variations converted initially uniform random and homogeneously connected networks, in which every neuron sent and received equal numbers of synapses with equal synaptic strength distributions, to highly heterogeneous networks in which the number of synapses per neuron, as well as average synaptic strength of synapses from or to a neuron were variable. By evaluating the impact of each variable on the network structure and dynamics, and their similarity to the experimental data, we could falsify the uniform random sparse connectivity hypothesis for 7 of 36 connectivity parameters, but we also confirmed the hypothesis in 8 cases. Twenty-one parameters had no substantial impact on the results of the test protocols we used.},
author = {Tomm, Christian and Avermann, Michael and Petersen, Carl and Gerstner, Wulfram and Vogels, Tim P},
issn = {1522-1598},
journal = {Journal of Neurophysiology},
number = {8},
pages = {1801--1814},
publisher = {American Physiological Society},
title = {{Connection-type-specific biases make uniform random network models consistent with cortical recordings}},
doi = {10.1152/jn.00629.2013},
volume = {112},
year = {2014},
}
@inproceedings{1374,
abstract = {We study two-player zero-sum games over infinite-state graphs equipped with ωB and finitary conditions. Our first contribution is about the strategy complexity, i.e the memory required for winning strategies: we prove that over general infinite-state graphs, memoryless strategies are sufficient for finitary Büchi, and finite-memory suffices for finitary parity games. We then study pushdown games with boundedness conditions, with two contributions. First we prove a collapse result for pushdown games with ωB-conditions, implying the decidability of solving these games. Second we consider pushdown games with finitary parity along with stack boundedness conditions, and show that solving these games is EXPTIME-complete.},
author = {Chatterjee, Krishnendu and Fijalkow, Nathanaël},
booktitle = {22nd EACSL Annual Conference on Computer Science Logic},
location = {Torino, Italy},
pages = {181 -- 196},
publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
title = {{Infinite-state games with finitary conditions}},
doi = {10.4230/LIPIcs.CSL.2013.181},
volume = {23},
year = {2013},
}
@inproceedings{1385,
abstract = {It is often difficult to correctly implement a Boolean controller for a complex system, especially when concurrency is involved. Yet, it may be easy to formally specify a controller. For instance, for a pipelined processor it suffices to state that the visible behavior of the pipelined system should be identical to a non-pipelined reference system (Burch-Dill paradigm). We present a novel procedure to efficiently synthesize multiple Boolean control signals from a specification given as a quantified first-order formula (with a specific quantifier structure). Our approach uses uninterpreted functions to abstract details of the design. We construct an unsatisfiable SMT formula from the given specification. Then, from just one proof of unsatisfiability, we use a variant of Craig interpolation to compute multiple coordinated interpolants that implement the Boolean control signals. Our method avoids iterative learning and back-substitution of the control functions. We applied our approach to synthesize a controller for a simple two-stage pipelined processor, and present first experimental results.},
author = {Hofferek, Georg and Gupta, Ashutosh and Könighofer, Bettina and Jiang, Jie and Bloem, Roderick},
booktitle = {2013 Formal Methods in Computer-Aided Design},
location = {Portland, OR, United States},
pages = {77 -- 84},
publisher = {IEEE},
title = {{Synthesizing multiple boolean functions using interpolation on a single proof}},
doi = {10.1109/FMCAD.2013.6679394},
year = {2013},
}
@inproceedings{1387,
abstract = {Choices made by nondeterministic word automata depend on both the past (the prefix of the word read so far) and the future (the suffix yet to be read). In several applications, most notably synthesis, the future is diverse or unknown, leading to algorithms that are based on deterministic automata. Hoping to retain some of the advantages of nondeterministic automata, researchers have studied restricted classes of nondeterministic automata. Three such classes are nondeterministic automata that are good for trees (GFT; i.e., ones that can be expanded to tree automata accepting the derived tree languages, thus whose choices should satisfy diverse futures), good for games (GFG; i.e., ones whose choices depend only on the past), and determinizable by pruning (DBP; i.e., ones that embody equivalent deterministic automata). The theoretical properties and relative merits of the different classes are still open, having vagueness on whether they really differ from deterministic automata. In particular, while DBP ⊆ GFG ⊆ GFT, it is not known whether every GFT automaton is GFG and whether every GFG automaton is DBP. Also open is the possible succinctness of GFG and GFT automata compared to deterministic automata. We study these problems for ω-regular automata with all common acceptance conditions. We show that GFT=GFG⊃DBP, and describe a determinization construction for GFG automata.},
author = {Boker, Udi and Kuperberg, Denis and Kupferman, Orna and Skrzypczak, Michał},
location = {Riga, Latvia},
number = {PART 2},
pages = {89 -- 100},
publisher = {Springer},
title = {{Nondeterminism in the presence of a diverse or unknown future}},
doi = {10.1007/978-3-642-39212-2_11},
volume = {7966},
year = {2013},
}
@article{1442,
abstract = {We give a cohomological interpretation of both the Kac polynomial and the refined Donaldson-Thomas-invariants of quivers. This interpretation yields a proof of a conjecture of Kac from 1982 and gives a new perspective on recent work of Kontsevich-Soibelman. Thisis achieved by computing, via an arithmetic Fourier transform, the dimensions of the isotypical components of the cohomology of associated Nakajima quiver varieties under the action of a Weyl group. The generating function of the corresponding Poincare polynomials is an extension of Hua's formula for Kac polynomials of quivers involving Hall-Littlewood symmetric functions. The resulting formulae contain a wide range of information on the geometry of the quiver varieties.},
author = {Tamas Hausel and Letellier, Emmanuel and Rodríguez Villegas, Fernando},
journal = {Annals of Mathematics},
number = {3},
pages = {1147 -- 1168},
publisher = {Princeton University Press},
title = {{Positivity for Kac polynomials and DT-invariants of quivers}},
doi = {10.4007/annals.2013.177.3.8},
volume = {177},
year = {2013},
}
@inbook{1443,
abstract = {Here we survey several results and conjectures on the cohomology of the total space of the Hitchin system: the moduli space of semi-stable rank n and degree d Higgs bundles on a complex algebraic curve C. The picture emerging is a dynamic mixture of ideas originating in theoretical physics such as gauge theory and mirror symmetry, Weil conjectures in arithmetic algebraic geometry, representation theory of finite groups of Lie type and Langlands duality in number theory.},
author = {Tamas Hausel},
booktitle = {Handbook of Moduli: Volume II},
pages = {29 -- 70},
publisher = {International Press},
title = {{Global topology of the Hitchin system}},
volume = {25},
year = {2013},
}
@article{1470,
abstract = {We show that a natural isomorphism between the rational cohomology groups of the two zero-dimensional Hilbert schemes of n-points of two surfaces, the affine plane minus the axes and the cotangent bundle of an elliptic curve, exchanges the weight filtration on the first set of cohomology groups with the perverse Leray filtration associated with a natural fibration on the second set of cohomology groups. We discuss some associated hard Lefschetz phenomena.},
author = {De Cataldo, Mark A and Tamas Hausel and Migliorini, Luca},
journal = {Journal of Singularities},
pages = {23 -- 38},
publisher = {Worldwide Center of Mathematics},
title = {{Exchange between perverse and weight filtration for the Hilbert schemes of points of two surfaces}},
doi = {10.5427/jsing.2013.7c},
volume = {7},
year = {2013},
}
@article{1759,
abstract = {We report an electric-field-induced giant modulation of the hole g factor in SiGe nanocrystals. The observed effect is ascribed to a so-far overlooked contribution to the g factor that stems from the mixing between heavy- and light-hole wave functions. We show that the relative displacement between the confined heavy- and light-hole states, occurring upon application of the electric field, alters their mixing strength leading to a strong nonmonotonic modulation of the g factor.},
author = {Ares, Natalia and Golovach, Vitaly N and Georgios Katsaros and Stoffel, Mathieu and Fournel, Frank and Glazman, Leonid I and Schmidt, Oliver G and De Franceschi, Silvano},
journal = {Physical Review Letters},
number = {4},
publisher = {American Physical Society},
title = {{Nature of tunable hole g factors in quantum dots}},
doi = {10.1103/PhysRevLett.110.046602},
volume = {110},
year = {2013},
}
@article{1760,
abstract = {We report on hole g-factor measurements in three terminal SiGe self-assembled quantum dot devices with a top gate electrode positioned very close to the nanostructure. Measurements of both the perpendicular as well as the parallel g-factor reveal significant changes for a small modulation of the top gate voltage. From the observed modulations, we estimate that, for realistic experimental conditions, hole spins can be electrically manipulated with Rabi frequencies in the order of 100 MHz. This work emphasises the potential of hole-based nano-devices for efficient spin manipulation by means of the g-tensor modulation technique.},
author = {Ares, Natalia and Georgios Katsaros and Golovach, Vitaly N and Zhang, Jianjun and Prager, Aaron A and Glazman, Leonid I and Schmidt, Oliver G and De Franceschi, Silvano},
journal = {Applied Physics Letters},
number = {26},
publisher = {American Institute of Physics},
title = {{SiGe quantum dots for fast hole spin Rabi oscillations}},
doi = {10.1063/1.4858959},
volume = {103},
year = {2013},
}
@article{1786,
abstract = {We report the experimental observation and a theoretical explanation of collective suppression of linewidths for multiple superconducting qubits coupled to a good cavity. This demonstrates how strong qubit-cavity coupling can significantly modify the dephasing and dissipation processes that might be expected for individual qubits, and can potentially improve coherence times in many-body circuit QED.},
author = {Nissen, Felix and Johannes Fink and Mlynek, Jonas A and Wallraff, Andreas and Keeling, Jonathan M},
journal = {Physical Review Letters},
number = {20},
publisher = {American Physical Society},
title = {{Collective suppression of linewidths in circuit QED}},
doi = {10.1103/PhysRevLett.110.203602},
volume = {110},
year = {2013},
}
@article{2009,
abstract = {Traditional statistical methods for confidentiality protection of statistical databases do not scale well to deal with GWAS databases especially in terms of guarantees regarding protection from linkage to external information. The more recent concept of differential privacy, introduced by the cryptographic community, is an approach which provides a rigorous definition of privacy with meaningful privacy guarantees in the presence of arbitrary external information, although the guarantees may come at a serious price in terms of data utility. Building on such notions, we propose new methods to release aggregate GWAS data without compromising an individual’s privacy. We present methods for releasing differentially private minor allele frequencies, chi-square statistics and p-values. We compare these approaches on simulated data and on a GWAS study of canine hair length involving 685 dogs. We also propose a privacy-preserving method for finding genome-wide associations based on a differentially-private approach to penalized logistic regression.},
author = {Uhler, Caroline and Slavkovic, Aleksandra and Fienberg, Stephen},
journal = {Journal of Privacy and Confidentiality },
number = {1},
pages = {137 -- 166},
publisher = {Carnegie Mellon University},
title = {{Privacy-preserving data sharing for genome-wide association studies}},
doi = {10.29012/jpc.v5i1.629},
volume = {5},
year = {2013},
}
@article{2010,
abstract = {Many algorithms for inferring causality rely heavily on the faithfulness assumption. The main justification for imposing this assumption is that the set of unfaithful distributions has Lebesgue measure zero, since it can be seen as a collection of hypersurfaces in a hypercube. However, due to sampling error the faithfulness condition alone is not sufficient for statistical estimation, and strong-faithfulness has been proposed and assumed to achieve uniform or high-dimensional consistency. In contrast to the plain faithfulness assumption, the set of distributions that is not strong-faithful has nonzero Lebesgue measure and in fact, can be surprisingly large as we show in this paper. We study the strong-faithfulness condition from a geometric and combinatorial point of view and give upper and lower bounds on the Lebesgue measure of strong-faithful distributions for various classes of directed acyclic graphs. Our results imply fundamental limitations for the PC-algorithm and potentially also for other algorithms based on partial correlation testing in the Gaussian case.},
author = {Uhler, Caroline and Raskutti, Garvesh and Bühlmann, Peter and Yu, Bin},
journal = {The Annals of Statistics},
number = {2},
pages = {436 -- 463},
publisher = {Institute of Mathematical Statistics},
title = {{Geometry of the faithfulness assumption in causal inference}},
doi = {10.1214/12-AOS1080},
volume = {41},
year = {2013},
}
@article{2117,
abstract = {We prove new upper and lower bounds for Banach space-valued stochastic integrals with respect to a compensated Poisson random measure. Our estimates apply to Banach spaces with non-trivial martingale (co)type and extend various results in the literature. We also develop a Malliavin framework to interpret Poisson stochastic integrals as vector-valued Skorohod integrals, and prove a Clark-Ocone representation formula.},
author = {Dirksen, Sjoerd and Jan Maas and van Neerven, Jan M},
journal = {Electronic Journal of Probability},
publisher = {Institute of Mathematical Statistics},
title = {{Poisson stochastic integration in Banach spaces}},
doi = {10.1214/EJP.v18-2945 },
volume = {18},
year = {2013},
}
@article{2129,
abstract = {This paper continues the investigation of `Wasserstein-like' transportation distances for probability measures on discrete sets. We prove that the discrete transportation metrics on the d-dimensional discrete torus with mesh size 1/N converge, when N→∞, to the standard 2-Wasserstein distance W_2 on the continuous torus in the sense of Gromov-Hausdorff. This is the first convergence result for the recently developed discrete transportation metrics. The result shows the compatibility between these metrics and the well-established 2-Wasserstein metric.
},
author = {Gigli, Nicola and Jan Maas},
journal = {SIAM Journal on Mathematical Analysis},
number = {2},
pages = {879 -- 899},
publisher = {Society for Industrial and Applied Mathematics },
title = {{Gromov-Hausdorff convergence of discrete transportation metrics}},
doi = {10.1137/120886315 },
volume = {45},
year = {2013},
}
@article{2139,
abstract = {Recently it has been shown that pairs of atoms can form metastable bonds due to non-conservative forces induced by dissipation [Lemeshko&Weimer, Nature Comm. 4, 2230 (2013)]. Here we study the dynamics of interaction-induced coherent population trapping - the process responsible for the formation of dissipatively bound molecules. We derive the effective dissipative potentials induced between ultracold atoms by laser light, and study the time evolution of the scattering states. We demonstrate that binding occurs on short timescales of ~10 microseconds, even if the initial kinetic energy of the atoms significantly exceeds the depth of the dissipative potential. Dissipatively-bound molecules with preordained bond lengths and vibrational wavefunctions can be created and detected in current experiments with ultracold atoms.},
author = {Mikhail Lemeshko},
journal = {Frontiers Physics},
number = {17},
publisher = {Frontiers Media},
title = {{Manipulating scattering of ultracold atoms with light-induced dissipation}},
doi = {10.3389/fphy.2013.00017},
volume = {1},
year = {2013},
}
@article{2152,
author = {Bhongale, Satyan G and Mathey, Ludwig and Zhao, Erhai and Yelin, Susanne F and Mikhail Lemeshko},
journal = {Physical Review Letters},
number = {23},
publisher = {American Physical Society},
title = {{Erratum: Quantum phases of quadrupolar fermi gases in optical lattices}},
doi = {10.1103/PhysRevLett.111.239901},
volume = {111},
year = {2013},
}
@inproceedings{2181,
abstract = {There is a trade-off between performance and correctness in implementing concurrent data structures. Better performance may be achieved at the expense of relaxing correctness, by redefining the semantics of data structures. We address such a redefinition of data structure semantics and present a systematic and formal framework for obtaining new data structures by quantitatively relaxing existing ones. We view a data structure as a sequential specification S containing all "legal" sequences over an alphabet of method calls. Relaxing the data structure corresponds to defining a distance from any sequence over the alphabet to the sequential specification: the k-relaxed sequential specification contains all sequences over the alphabet within distance k from the original specification. In contrast to other existing work, our relaxations are semantic (distance in terms of data structure states). As an instantiation of our framework, we present two simple yet generic relaxation schemes, called out-of-order and stuttering relaxation, along with several ways of computing distances. We show that the out-of-order relaxation, when further instantiated to stacks, queues, and priority queues, amounts to tolerating bounded out-of-order behavior, which cannot be captured by a purely syntactic relaxation (distance in terms of sequence manipulation, e.g. edit distance). We give concurrent implementations of relaxed data structures and demonstrate that bounded relaxations provide the means for trading correctness for performance in a controlled way. The relaxations are monotonic which further highlights the trade-off: increasing k increases the number of permitted sequences, which as we demonstrate can lead to better performance. Finally, since a relaxed stack or queue also implements a pool, we actually have new concurrent pool implementations that outperform the state-of-the-art ones.},
author = {Henzinger, Thomas A and Kirsch, Christoph and Payer, Hannes and Sezgin, Ali and Sokolova, Ana},
booktitle = {Proceedings of the 40th annual ACM SIGPLAN-SIGACT symposium on Principles of programming language},
isbn = {978-1-4503-1832-7},
location = {Rome, Italy},
pages = {317 -- 328},
publisher = {ACM},
title = {{Quantitative relaxation of concurrent data structures}},
doi = {10.1145/2429069.2429109},
year = {2013},
}
@article{2204,
abstract = {We introduce a new platform for quantum simulation of many-body systems based on nonspherical atoms or molecules with zero dipole moments but possessing a significant value of electric quadrupole moments. We consider a quadrupolar Fermi gas trapped in a 2D square optical lattice, and show that the peculiar symmetry and broad tunability of the quadrupole-quadrupole interaction results in a rich phase diagram encompassing unconventional BCS and charge density wave phases, and opens up a perspective to create a topological superfluid. Quadrupolar species, such as metastable alkaline-earth atoms and homonuclear molecules, are stable against chemical reactions and collapse and are readily available in experiment at high densities.},
author = {Bhongale, Satyan G and Mathey, Ludwig and Zhao, Erhai and Yelin, Susanne F and Mikhail Lemeshko},
journal = {Physical Review Letters},
number = {15},
publisher = {American Physical Society},
title = {{Quantum phases of quadrupolar fermi gases in optical lattices}},
doi = {10.1103/PhysRevLett.110.155301},
volume = {110},
year = {2013},
}
@misc{2205,
abstract = {The goal of the present article is to review the major developments that have led to the current understanding of molecule-field interactions and experimental methods for manipulating molecules with electromagnetic fields. Molecule-field interactions are at the core of several, seemingly distinct areas of molecular physics. This is reflected in the organisation of this article, which includes sections on field control of molecular beams, external field traps for cold molecules, control of molecular orientation and molecular alignment, manipulation of molecules by non-conservative forces, ultracold molecules and ultracold chemistry, controlled many-body phenomena, entanglement of molecules and dipole arrays, and stability of molecular systems in high-frequency super-intense laser fields. The article contains 852 references.},
author = {Mikhail Lemeshko and Krems, Roman V and Doyle, John M and Kais, Sabre},
booktitle = {Molecular Physics},
number = {12-13},
pages = {1648 -- 1682},
publisher = {Taylor & Francis},
title = {{Manipulation of molecules with electromagnetic fields}},
doi = {10.1080/00268976.2013.813595},
volume = {111},
year = {2013},
}
@article{2206,
abstract = {Magnetic impurities embedded in inert solids can exhibit long coherence times and interact with one another via their intrinsic anisotropic dipolar interaction. We argue that, as a consequence of these properties, disordered ensembles of magnetic impurities provide an effective platform for realizing a controllable, tunable version of the dipolar quantum spin glass seen in LiHoxY1-xF4. Specifically, we propose and analyze a system composed of dysprosium atoms embedded in solid helium. We describe the phase diagram of the system and discuss the realizability and detectability of the quantum spin glass and antiglass phases.},
author = {Mikhail Lemeshko and Yao, Norman Y and Gorshkov, Alexey V and Weimer, Hendrik and Bennett, Steven D and Momose, Takamasa and Gopalakrishnan, Sarang},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {1},
publisher = {American Physical Society},
title = {{Controllable quantum spin glasses with magnetic impurities embedded in quantum solids}},
doi = {10.1103/PhysRevB.88.014426},
volume = {88},
year = {2013},
}
@article{2207,
abstract = {The formation of molecules and supramolecular structures results from bonding by conservative forces acting among electrons and nuclei and giving rise to equilibrium configurations defined by minima of the interaction potential. Here we show that bonding can also occur by the non-conservative forces responsible for interaction-induced coherent population trapping. The bound state arises in a dissipative process and manifests itself as a stationary state at a preordained interatomic distance. Remarkably, such a dissipative bonding is present even when the interactions among the atoms are purely repulsive. The dissipative bound states can be created and studied spectroscopically in present-day experiments with ultracold atoms or molecules and can potentially serve for cooling strongly interacting quantum gases.},
author = {Mikhail Lemeshko and Weimer, Hendrik},
journal = {Nature Communications},
publisher = {Nature Publishing Group},
title = {{Dissipative binding of atoms by non-conservative forces}},
doi = {10.1038/ncomms3230},
volume = {4},
year = {2013},
}