TY - JOUR
AB - 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.
AU - Nissen, Felix
AU - Johannes Fink
AU - Mlynek, Jonas A
AU - Wallraff, Andreas
AU - Keeling, Jonathan M
ID - 1786
IS - 20
JF - Physical Review Letters
TI - Collective suppression of linewidths in circuit QED
VL - 110
ER -
TY - JOUR
AB - 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.
AU - Uhler, Caroline
AU - Slavkovic, Aleksandra
AU - Fienberg, Stephen
ID - 2009
IS - 1
JF - Journal of Privacy and Confidentiality
TI - Privacy-preserving data sharing for genome-wide association studies
VL - 5
ER -
TY - JOUR
AB - 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.
AU - Uhler, Caroline
AU - Raskutti, Garvesh
AU - Bühlmann, Peter
AU - Yu, Bin
ID - 2010
IS - 2
JF - The Annals of Statistics
TI - Geometry of the faithfulness assumption in causal inference
VL - 41
ER -
TY - JOUR
AB - 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.
AU - Dirksen, Sjoerd
AU - Jan Maas
AU - van Neerven, Jan M
ID - 2117
JF - Electronic Journal of Probability
TI - Poisson stochastic integration in Banach spaces
VL - 18
ER -
TY - JOUR
AB - 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.
AU - Gigli, Nicola
AU - Jan Maas
ID - 2129
IS - 2
JF - SIAM Journal on Mathematical Analysis
TI - Gromov-Hausdorff convergence of discrete transportation metrics
VL - 45
ER -
TY - JOUR
AB - 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.
AU - Mikhail Lemeshko
ID - 2139
IS - 17
JF - Frontiers Physics
TI - Manipulating scattering of ultracold atoms with light-induced dissipation
VL - 1
ER -
TY - JOUR
AU - Bhongale, Satyan G
AU - Mathey, Ludwig
AU - Zhao, Erhai
AU - Yelin, Susanne F
AU - Mikhail Lemeshko
ID - 2152
IS - 23
JF - Physical Review Letters
TI - Erratum: Quantum phases of quadrupolar fermi gases in optical lattices
VL - 111
ER -
TY - CONF
AB - 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.
AU - Henzinger, Thomas A
AU - Kirsch, Christoph
AU - Payer, Hannes
AU - Sezgin, Ali
AU - Sokolova, Ana
ID - 2181
SN - 978-1-4503-1832-7
T2 - Proceedings of the 40th annual ACM SIGPLAN-SIGACT symposium on Principles of programming language
TI - Quantitative relaxation of concurrent data structures
ER -
TY - JOUR
AB - 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.
AU - Bhongale, Satyan G
AU - Mathey, Ludwig
AU - Zhao, Erhai
AU - Yelin, Susanne F
AU - Mikhail Lemeshko
ID - 2204
IS - 15
JF - Physical Review Letters
TI - Quantum phases of quadrupolar fermi gases in optical lattices
VL - 110
ER -
TY - GEN
AB - 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.
AU - Mikhail Lemeshko
AU - Krems, Roman V
AU - Doyle, John M
AU - Kais, Sabre
ID - 2205
IS - 12-13
T2 - Molecular Physics
TI - Manipulation of molecules with electromagnetic fields
VL - 111
ER -
TY - JOUR
AB - 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.
AU - Mikhail Lemeshko
AU - Yao, Norman Y
AU - Gorshkov, Alexey V
AU - Weimer, Hendrik
AU - Bennett, Steven D
AU - Momose, Takamasa
AU - Gopalakrishnan, Sarang
ID - 2206
IS - 1
JF - Physical Review B - Condensed Matter and Materials Physics
TI - Controllable quantum spin glasses with magnetic impurities embedded in quantum solids
VL - 88
ER -
TY - JOUR
AB - 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.
AU - Mikhail Lemeshko
AU - Weimer, Hendrik
ID - 2207
JF - Nature Communications
TI - Dissipative binding of atoms by non-conservative forces
VL - 4
ER -
TY - CONF
AB - A straight skeleton is a well-known geometric structure, and several algorithms exist to construct the straight skeleton for a given polygon. In this paper, we ask the reverse question: Given the straight skeleton (in form of a tree with a drawing in the plane, but with the exact position of the leaves unspecified), can we reconstruct the polygon? We show that in most cases there exists at most one polygon; in the remaining case there is an infinite number of polygons determined by one angle that can range in an interval. We can find this (set of) polygon(s) in linear time in the Real RAM computer model.
AU - Biedl, Therese
AU - Held, Martin
AU - Huber, Stefan
ID - 2210
T2 - 29th European Workshop on Computational Geometry
TI - Reconstructing polygons from embedded straight skeletons
ER -
TY - CONF
AB - We describe new extensions of the Vampire theorem prover for computing tree interpolants. These extensions generalize Craig interpolation in Vampire, and can also be used to derive sequence interpolants. We evaluated our implementation on a large number of examples over the theory of linear integer arithmetic and integer-indexed arrays, with and without quantifiers. When compared to other methods, our experiments show that some examples could only be solved by our implementation.
AU - Blanc, Régis
AU - Gupta, Ashutosh
AU - Kovács, Laura
AU - Kragl, Bernhard
ID - 2237
TI - Tree interpolation in Vampire
VL - 8312
ER -
TY - CONF
AB - We show that modal logic over universally first-order definable classes of transitive frames is decidable. More precisely, let K be an arbitrary class of transitive Kripke frames definable by a universal first-order sentence. We show that the global and finite global satisfiability problems of modal logic over K are decidable in NP, regardless of choice of K. We also show that the local satisfiability and the finite local satisfiability problems of modal logic over K are decidable in NEXPTIME.
AU - Michaliszyn, Jakub
AU - Otop, Jan
ID - 2243
TI - Elementary modal logics over transitive structures
VL - 23
ER -
TY - JOUR
AB - Cooperative behavior, where one individual incurs a cost to help another, is a wide spread phenomenon. Here we study direct reciprocity in the context of the alternating Prisoner's Dilemma. We consider all strategies that can be implemented by one and two-state automata. We calculate the payoff matrix of all pairwise encounters in the presence of noise. We explore deterministic selection dynamics with and without mutation. Using different error rates and payoff values, we observe convergence to a small number of distinct equilibria. Two of them are uncooperative strict Nash equilibria representing always-defect (ALLD) and Grim. The third equilibrium is mixed and represents a cooperative alliance of several strategies, dominated by a strategy which we call Forgiver. Forgiver cooperates whenever the opponent has cooperated; it defects once when the opponent has defected, but subsequently Forgiver attempts to re-establish cooperation even if the opponent has defected again. Forgiver is not an evolutionarily stable strategy, but the alliance, which it rules, is asymptotically stable. For a wide range of parameter values the most commonly observed outcome is convergence to the mixed equilibrium, dominated by Forgiver. Our results show that although forgiving might incur a short-term loss it can lead to a long-term gain. Forgiveness facilitates stable cooperation in the presence of exploitation and noise.
AU - Zagorsky, Benjamin
AU - Reiter, Johannes
AU - Chatterjee, Krishnendu
AU - Nowak, Martin
ID - 2247
IS - 12
JF - PLoS One
TI - Forgiver triumphs in alternating prisoner's dilemma
VL - 8
ER -
TY - CONF
AB - We consider two systems (α1,...,αm) and (β1,...,βn) of curves drawn on a compact two-dimensional surface ℳ with boundary. Each αi and each βj is either an arc meeting the boundary of ℳ at its two endpoints, or a closed curve. The αi are pairwise disjoint except for possibly sharing endpoints, and similarly for the βj. We want to "untangle" the βj from the αi by a self-homeomorphism of ℳ; more precisely, we seek an homeomorphism φ: ℳ → ℳ fixing the boundary of ℳ pointwise such that the total number of crossings of the αi with the φ(βj) is as small as possible. This problem is motivated by an application in the algorithmic theory of embeddings and 3-manifolds. We prove that if ℳ is planar, i.e., a sphere with h ≥ 0 boundary components ("holes"), then O(mn) crossings can be achieved (independently of h), which is asymptotically tight, as an easy lower bound shows. In general, for an arbitrary (orientable or nonorientable) surface ℳ with h holes and of (orientable or nonorientable) genus g ≥ 0, we obtain an O((m + n)4) upper bound, again independent of h and g.
AU - Matoušek, Jiří
AU - Sedgwick, Eric
AU - Tancer, Martin
AU - Wagner, Uli
ID - 2244
TI - Untangling two systems of noncrossing curves
VL - 8242
ER -
TY - CONF
AB - In a digital signature scheme with message recovery, rather than transmitting the message m and its signature σ, a single enhanced signature τ is transmitted. The verifier is able to recover m from τ and at the same time verify its authenticity. The two most important parameters of such a scheme are its security and overhead |τ| − |m|. A simple argument shows that for any scheme with “n bits security” |τ| − |m| ≥ n, i.e., the overhead is lower bounded by the security parameter n. Currently, the best known constructions in the random oracle model are far from this lower bound requiring an overhead of n + logq h , where q h is the number of queries to the random oracle. In this paper we give a construction which basically matches the n bit lower bound. We propose a simple digital signature scheme with n + o(logq h ) bits overhead, where q h denotes the number of random oracle queries.
Our construction works in two steps. First, we propose a signature scheme with message recovery having optimal overhead in a new ideal model, the random invertible function model. Second, we show that a four-round Feistel network with random oracles as round functions is tightly “public-indifferentiable” from a random invertible function. At the core of our indifferentiability proof is an almost tight upper bound for the expected number of edges of the densest “small” subgraph of a random Cayley graph, which may be of independent interest.
AU - Kiltz, Eike
AU - Pietrzak, Krzysztof Z
AU - Szegedy, Mario
ID - 2258
TI - Digital signatures with minimal overhead from indifferentiable random invertible functions
VL - 8042
ER -
TY - CONF
AB - The learning with rounding (LWR) problem, introduced by Banerjee, Peikert and Rosen at EUROCRYPT ’12, is a variant of learning with errors (LWE), where one replaces random errors with deterministic rounding. The LWR problem was shown to be as hard as LWE for a setting of parameters where the modulus and modulus-to-error ratio are super-polynomial. In this work we resolve the main open problem and give a new reduction that works for a larger range of parameters, allowing for a polynomial modulus and modulus-to-error ratio. In particular, a smaller modulus gives us greater efficiency, and a smaller modulus-to-error ratio gives us greater security, which now follows from the worst-case hardness of GapSVP with polynomial (rather than super-polynomial) approximation factors.
As a tool in the reduction, we show that there is a “lossy mode” for the LWR problem, in which LWR samples only reveal partial information about the secret. This property gives us several interesting new applications, including a proof that LWR remains secure with weakly random secrets of sufficient min-entropy, and very simple constructions of deterministic encryption, lossy trapdoor functions and reusable extractors.
Our approach is inspired by a technique of Goldwasser et al. from ICS ’10, which implicitly showed the existence of a “lossy mode” for LWE. By refining this technique, we also improve on the parameters of that work to only requiring a polynomial (instead of super-polynomial) modulus and modulus-to-error ratio.
AU - Alwen, Joel F
AU - Krenn, Stephan
AU - Pietrzak, Krzysztof Z
AU - Wichs, Daniel
ID - 2259
IS - 1
TI - Learning with rounding, revisited: New reduction properties and applications
VL - 8042
ER -
TY - CONF
AB - Direct Anonymous Attestation (DAA) is one of the most complex cryptographic protocols deployed in practice. It allows an embedded secure processor known as a Trusted Platform Module (TPM) to attest to the configuration of its host computer without violating the owner’s privacy. DAA has been standardized by the Trusted Computing Group and ISO/IEC.
The security of the DAA standard and all existing schemes is analyzed in the random-oracle model. We provide the first constructions of DAA in the standard model, that is, without relying on random oracles. Our constructions use new building blocks, including the first efficient signatures of knowledge in the standard model, which have many applications beyond DAA.
AU - Bernhard, David
AU - Fuchsbauer, Georg
AU - Ghadafi, Essam
ID - 2260
TI - Efficient signatures of knowledge and DAA in the standard model
VL - 7954
ER -