Bulletin of the American Physical Society
APS March Meeting 2022
Volume 67, Number 3
Monday–Friday, March 14–18, 2022; Chicago
Session T45: Kardar-Parisi-Zhang Universality in Quantum Many Body SystemsInvited Live Streamed
|
Hide Abstracts |
Sponsoring Units: DCMP DAMOP Chair: Sarang Gopalakrishnan Room: McCormick Place W-375D |
Thursday, March 17, 2022 11:30AM - 12:06PM |
T45.00001: Detection of Kardar-Parisi-Zhang hydrodynamics in a quantum Heisenberg spin chain Invited Speaker: David A Tennant Classical hydrodynamics is a remarkably versatile description of the coarse-grained behavior of many-particle systems once local equilibrium has been established. The form of the hydrodynamical equations is determined primarily by the conserved quantities present in a system. Some quantum spin chains are known to possess, even in the simplest cases, a greatly expanded set of conservation laws, and recent work suggests that these laws strongly modify collective spin dynamics, even at high temperature. Here, by probing the dynamical exponent of the one-dimensional Heisenberg antiferromagnet KCuF3 with neutron scattering, we find evidence that the spin dynamics are well described by the dynamical exponent z = 3/2, which is consistent with the recent theoretical conjecture that the dynamics of this quantum system are described by the Kardar–Parisi–Zhang universality class. This observation shows that low-energy inelastic neutron scattering at moderate temperatures can reveal the details of emergent quantum fluid properties like those arising in non-Fermi liquids in higher dimensions. |
Thursday, March 17, 2022 12:06PM - 12:42PM |
T45.00002: Initial condition dependence of KPZ universality: from soft matter experiments to quantum spin chains Invited Speaker: Kazumasa A Takeuchi While the Kardar-Parisi-Zhang (KPZ) universality class has been established as a prominent class for random growth processes and many other stochastic problems in non-equilibrium but classical physics, it is only recently that KPZ turned out to rule quantum spin chains of the isotropic Heisenberg model. This implies that a wealth of knowledge from classical KPZ systems may be utilized to unveil characteristic statistical properties of the fluctuating quantum spins. Particularly noteworthy is the fact that the KPZ class splits into a few "universality subclasses" depending on the initial condition [1], which may potentially contribute to characterize thermalization of such quantum spins. |
Thursday, March 17, 2022 12:42PM - 1:18PM |
T45.00003: Kardar-Parisi-Zhang universality from soft modes in spin chains Invited Speaker: Vir B Bulchandani
|
Thursday, March 17, 2022 1:18PM - 1:54PM |
T45.00004: Superuniversality of superdifusion in integrable many-body systems with nonabelian symmetries Invited Speaker: Tomasz Prosen I will present a plethora of computational evidence for superuniversality of superdiffusive spin (or, generally, Noether charge) transport in integrable spin chains with arbitrary non-abelian symmetries. The most prominent example is the quantum Heisenberg magnet, while other quantum and classical integrable chains with non-abelian Lie group symmetries are shown to yield identical phenomenology. The two-point functions (e.g. dynamical spin structure factor) at high temperature are shown to be described by Kardar-Parisi-Zhang (KPZ) universality class with dynamical exponent z=3/2. This is remarkable, as KPZ universality in stochastic growth and related processes applies to manifesly non-equilibrium situations, while in the present context of equilibrium spin transport we show that KPZ universality breaks down to diffusive universality when introducing non-equilibrium initial states with a finite magnetization bias which break the non-abelian symmetry. The talk will be concluded by the discussion of the most pressing open theoretical questions. |
Thursday, March 17, 2022 1:54PM - 2:30PM |
T45.00005: Observation of Kardar-Parisi-Zhang superdiffusion in a Heisenberg quantum magnet Invited Speaker: David Wei The Kardar-Parisi-Zhang universality class describes the coarse-grained dynamics of numerous classical stochastic models. Surprisingly, it was recently conjectured, that spin transport in the one-dimensional (1D) quantum Heisenberg model falls into this class. In our experiment, we employ a cold-atom quantum simulator to verify this conjecture by studying the hydrodynamic relaxation of spin-domain walls. We find that transport is superdiffusive and indeed obeys the characteristic KPZ space-time scaling with dynamical exponent z=3/2. We observe that superdiffusion breaks down when probing dynamics both in the 2D model and in the net-magnetized 1D model, which supports the notion that integrability and the non-abelian SU(2) symmetry of the 1D Heisenberg model give rise to its KPZ dynamics. Finally, we leverage the single-spin-sensitive detection enabled by our quantum-gas microscope to measure spin-transport statistics, which yields a clear signature of the non-linearity that is a hallmark of KPZ universality. |
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