Time:  10:00am  (UTC/GMT+8:00, Beijing/Shanghai), Nov. 26 (Fri.) , 2021

Venue: M830, M Building of IOP, CAS

Speaker: Rubem Mondaini (Beijing Computational Science Research Center)

Abstract:

The "sign problem" (SP) is the fundamental limitation to simulations of strongly correlated materials in condensed matter physics, solving quantum chromodynamics at finite baryon density, and computational studies of nuclear matter. It is often argued that the SP is not intrinsic to the physics of particular Hamiltonians, since the details of how it onsets, and its eventual occurrence, can be altered by the choice of algorithm or many particle basis. Despite that, I plan to show in this talk that the SP in determinant quantum Monte Carlo (DQMC) is quantitatively linked to quantum critical behavior. This demonstration is done via simulations of a number of fundamental models of condensed matter physics, all of whose critical properties are relatively well understood.

References:

[1] Rubem Mondaini, Sabyasachi Tarat, Richard T. Scalettar, Quantum critical points and the sign problem, arXiv preprint arXiv:2108.08974
[2] Rubem Mondaini, Sabyasachi Tarat, Richard T. Scalettar, Universality and Critical Exponents of the Fermion Sign Problem (submitted)

About the Speaker:

Rubem obtained his PhD in Physics at the Federal University of Rio de Janeiro (2012), where his main lines of research encompass the following subjects: Strongly Correlated/Quantum many-body systems in and out-of-equilibrium, with specific interests in Magnetic Multilayers, Transport Properties in Many-Body Systems, Disorder in Graphene, Superconductivity in Cuprates, Thermalization and Many-Body Localization. After postdoc positions at the Pennsylvania State University and the University of California, Davis, he moved to China,\ where, currently, holds a tenure-track faculty position as Assistant Professor at the Beijing Computational Science Research Center (CSRC).