Regensburg 2019 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 4: Nonequilibrium Quantum Many-Body Systems 1 (joint session TT/DY)

TT 4.5: Vortrag

Montag, 1. April 2019, 10:30–10:45, H22

Time-dependent wave functions with multiple correlators for the Hubbard model in nonequilibrium — •Patricia Mayer¹, Masud Haque², and Marcus Kollar¹ — ¹Theoretische Physik III, Universität Augsburg — ²Department of Theoretical Physics, Maynooth University, Ireland

For the solvable 1/r-Hubbard chain [1], the double occupation relaxes to nonthermal values after an interaction quench [2]. We apply time-dependent variational wave functions to this problem to assess their descriptive capabilities. We find that the Gutzwiller wave function, which acts on the Fermi sea with the exponentiated double occupation as correlator, can describe the time evolution accurately only for short times and then keeps oscillating with a single frequency, similar to the infinite-dimensional case [3]. On the other hand, in the Gutzwiller-Baeriswyl wave function the exponentiated kinetic energy is applied in turn to the Gutzwiller wave function [4], which leads to accurate expectation values up to longer times followed by a more complicated oscillating pattern. We conclude that multiple variational correlators substantially improve the description of Hubbard models in nonequilibrium.
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