@article{14756, abstract = {We prove the r-spin cobordism hypothesis in the setting of (weak) 2-categories for every positive integer r: the 2-groupoid of 2-dimensional fully extended r-spin TQFTs with given target is equivalent to the homotopy fixed points of an induced Spin 2r -action. In particular, such TQFTs are classified by fully dualisable objects together with a trivialisation of the rth power of their Serre automorphisms. For r=1, we recover the oriented case (on which our proof builds), while ordinary spin structures correspond to r=2. To construct examples, we explicitly describe Spin 2r​-homotopy fixed points in the equivariant completion of any symmetric monoidal 2-category. We also show that every object in a 2-category of Landau–Ginzburg models gives rise to fully extended spin TQFTs and that half of these do not factor through the oriented bordism 2-category.}, author = {Carqueville, Nils and Szegedy, Lorant}, issn = {1663-487X}, journal = {Quantum Topology}, keywords = {Geometry and Topology, Mathematical Physics}, number = {3}, pages = {467--532}, publisher = {European Mathematical Society}, title = {{Fully extended r-spin TQFTs}}, doi = {10.4171/qt/193}, volume = {14}, year = {2023}, } @article{10845, abstract = {We study an impurity with a resonance level whose position coincides with the Fermi energy of the surrounding Fermi gas. An impurity causes a rapid variation of the scattering phase shift for fermions at the Fermi surface, introducing a new characteristic length scale into the problem. We investigate manifestations of this length scale in the self-energy of the impurity and in the density of the bath. Our calculations reveal a model-independent deformation of the density of the Fermi gas, which is determined by the width of the resonance. To provide a broader picture, we investigate time evolution of the density in quench dynamics, and study the behavior of the system at finite temperatures. Finally, we briefly discuss implications of our findings for the Fermi-polaron problem.}, author = {Maslov, Mikhail and Lemeshko, Mikhail and Volosniev, Artem}, issn = {2643-1564}, journal = {Physical Review Research}, publisher = {American Physical Society}, title = {{Impurity with a resonance in the vicinity of the Fermi energy}}, doi = {10.1103/PhysRevResearch.4.013160}, volume = {4}, year = {2022}, } @article{10771, abstract = {A critical overview of the theory of the chirality-induced spin selectivity (CISS) effect, that is, phenomena in which the chirality of molecular species imparts significant spin selectivity to various electron processes, is provided. Based on discussions in a recently held workshop, and further work published since, the status of CISS effects—in electron transmission, electron transport, and chemical reactions—is reviewed. For each, a detailed discussion of the state-of-the-art in theoretical understanding is provided and remaining challenges and research opportunities are identified.}, author = {Evers, Ferdinand and Aharony, Amnon and Bar-Gill, Nir and Entin-Wohlman, Ora and Hedegård, Per and Hod, Oded and Jelinek, Pavel and Kamieniarz, Grzegorz and Lemeshko, Mikhail and Michaeli, Karen and Mujica, Vladimiro and Naaman, Ron and Paltiel, Yossi and Refaely-Abramson, Sivan and Tal, Oren and Thijssen, Jos and Thoss, Michael and Van Ruitenbeek, Jan M. and Venkataraman, Latha and Waldeck, David H. and Yan, Binghai and Kronik, Leeor}, issn = {15214095}, journal = {Advanced Materials}, number = {13}, publisher = {Wiley}, title = {{Theory of chirality induced spin selectivity: Progress and challenges}}, doi = {10.1002/adma.202106629}, volume = {34}, year = {2022}, } @article{11552, abstract = {Rotational dynamics of D2 molecules inside helium nanodroplets is induced by a moderately intense femtosecond pump pulse and measured as a function of time by recording the yield of HeD+ ions, created through strong-field dissociative ionization with a delayed femtosecond probe pulse. The yield oscillates with a period of 185 fs, reflecting field-free rotational wave packet dynamics, and the oscillation persists for more than 500 periods. Within the experimental uncertainty, the rotational constant BHe of the in-droplet D2 molecule, determined by Fourier analysis, is the same as Bgas for an isolated D2 molecule. Our observations show that the D2 molecules inside helium nanodroplets essentially rotate as free D2 molecules.}, author = {Qiang, Junjie and Zhou, Lianrong and Lu, Peifen and Lin, Kang and Ma, Yongzhe and Pan, Shengzhe and Lu, Chenxu and Jiang, Wenyu and Sun, Fenghao and Zhang, Wenbin and Li, Hui and Gong, Xiaochun and Averbukh, Ilya Sh and Prior, Yehiam and Schouder, Constant A. and Stapelfeldt, Henrik and Cherepanov, Igor and Lemeshko, Mikhail and Jäger, Wolfgang and Wu, Jian}, issn = {10797114}, journal = {Physical Review Letters}, number = {24}, publisher = {American Physical Society}, title = {{Femtosecond rotational dynamics of D2 molecules in superfluid helium nanodroplets}}, doi = {10.1103/PhysRevLett.128.243201}, volume = {128}, year = {2022}, } @article{11590, abstract = {We investigate the ground-state properties of weakly repulsive one-dimensional bosons in the presence of an attractive zero-range impurity potential. First, we derive mean-field solutions to the problem on a finite ring for the two asymptotic cases: (i) all bosons are bound to the impurity and (ii) all bosons are in a scattering state. Moreover, we derive the critical line that separates these regimes in the parameter space. In the thermodynamic limit, this critical line determines the maximum number of bosons that can be bound by the impurity potential, forming an artificial atom. Second, we validate the mean-field results using the flow equation approach and the multi-layer multi-configuration time-dependent Hartree method for atomic mixtures. While beyond-mean-field effects destroy long-range order in the Bose gas, the critical boson number is unaffected. Our findings are important for understanding such artificial atoms in low-density Bose gases with static and mobile impurities.}, author = {Brauneis, Fabian and Backert, Timothy G. and Mistakidis, Simeon I. and Lemeshko, Mikhail and Hammer, Hans Werner and Volosniev, Artem}, issn = {1367-2630}, journal = {New Journal of Physics}, number = {6}, publisher = {IOP Publishing}, title = {{Artificial atoms from cold bosons in one dimension}}, doi = {10.1088/1367-2630/ac78d8}, volume = {24}, year = {2022}, }