Bulletin of the American Physical Society
APS March Meeting 2022
Volume 67, Number 3
Monday–Friday, March 14–18, 2022; Chicago
Session Z15: Many-Body Localization: Phenomenology and InstabilitiesInvited Live Streamed
|
Hide Abstracts |
Sponsoring Units: DCMP DCOMP DAMOP Chair: Istvan Kovacs, Northwestern University Room: McCormick Place W-183C |
Friday, March 18, 2022 11:30AM - 12:06PM |
Z15.00001: A constructive theory of the numerically and experimentally accessible many-body localized phase Invited Speaker: Anushya Chandran The many-body localised (MBL) to thermal crossover observed in cold atom experiments and in numerical studies remains poorly understood, despite nearly a decade of intensive study. I will develop a model for the crossover in which the MBL chain is destabilised by many-body resonances. The model reproduces several observed properties of the crossover, identifies a large region of the observed phase diagram as only "apparent" or pre-thermal MBL, and makes new predictions for the scaling of thermalization time scales and eigenstate entropy in this apparent MBL region. |
Friday, March 18, 2022 12:06PM - 12:42PM |
Z15.00002: Many-body delocalization as symmetry-breaking Invited Speaker: Samuel J Garratt We present a framework in which the transition between a many-body localised (MBL) phase and an ergodic one is symmetry breaking. We consider random Floquet spin chains, expressing their averaged spectral form factor (SFF) as a function of time in terms of a transfer matrix that acts in the space direction. The SFF is determined by the leading eigenvalues of this transfer matrix. In the MBL phase the leading eigenvalue is unique, as in a symmetry-unbroken phase, while in the ergodic phase and at late times the leading eigenvalues are asymptotically degenerate, as in a system with degenerate symmetry-breaking phases. We identify the broken symmetry of the transfer matrix, introduce a local order parameter for the transition, and show that the associated correlation functions are long-ranged only in the ergodic phase. |
Friday, March 18, 2022 12:42PM - 1:18PM |
Z15.00003: Resonances and avalanches in many-body localized systems Invited Speaker: David A Huse I will review our current understanding, and lack thereof, of the regimes in the phase diagram of many-body localization, particularly for systems in one dimension with short-range interactions. |
Friday, March 18, 2022 1:18PM - 1:54PM |
Z15.00004: From avalanches to the Golden rule: numerical constraints on many-body localization Invited Speaker: Dries Sels
|
Friday, March 18, 2022 1:54PM - 2:30PM |
Z15.00005: Phenomenology of spectral functions in disordered spin chains Invited Speaker: Lev Vidmar Studies of disordered spin chains have recently experienced a renewed interest, inspired by the question to which extent the exact numerical calculations comply with the existence of a many-body localization phase transition. For the paradigmatic random field Heisenberg spin chains, many intriguing features were observed when the disorder is considerable compared to the spin interaction strength. Here, we introduce a phenomenological theory that may explain some of those features. The theory is based on the proximity to the noninteracting limit, in which the system is an Anderson insulator. Taking the spin imbalance as an exemplary observable, we demonstrate that the proximity to the local integrals of motion of the Anderson insulator determines the dynamics of the observable at infinite temperature. In finite interacting systems our theory quantitatively describes its integrated spectral function for a wide range of disorders. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700