2021/11/30 by Jan C. Louw, Stefan Kehrein · 1 citation
Physics and Astronomy · #cond-mat.str-el #cond-mat.dis-nn #hep-th #quant-ph
paper · pdf · doi:10.1103/physrevb.105.075117
published as Phys. Rev. B 105, 075117 (2022)
arxiv created 2022/02/16 · arxiv updated 2022/02/17
We investigate the non-equilibrium dynamics of complex Sachdev-Ye-Kitaev (SYK) models in the q→∞ limit, where q/2 denotes the order of the random Dirac fermion interaction. We extend previous results by Eberlein et al. [Phys. Rev. B 96, 205123 (2017)] to show that a single SYK q→∞ Hamiltonian for t≥ 0 is a perfect thermalizer in the sense that the local Green's function is instantaneously thermal. The only memories of the quantum state for t<0 are its charge density and its energy density at t=0. Our result is valid for all quantum states amenable to a~1/q-expansion, which are generated from an equilibrium SYK state in the asymptotic past and acted upon by an arbitrary combination of time-dependent SYK Hamiltonians for t<0. Importantly, this implies that a single SYK q→∞ Hamiltonian is a perfect thermalizer even for non-equilibrium states generated in this manner.