Infinite Grassmann Time-Evolving Matrix Product Operator Method in the Steady State

Fuente: arXiv
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Auteurs principaux: Guo, Chu, Chen, Ruofan
Format: Preprint
Publié: 2024
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author Guo, Chu
Chen, Ruofan
author_facet Guo, Chu
Chen, Ruofan
contents We present an infinite Grassmann time-evolving matrix product operator method for quantum impurity problems, which directly works in the steady state. The method embraces the well-established infinite matrix product state algorithms with the recently developed GTEMPO method, and benefits from both sides: it obtains real-time Green's functions without sampling noises and bath discretization error, it is applicable for any temperature without the sign problem, its computational cost is independent of the transient dynamics and does not scale with the number of baths. We benchmark the method on the finite-temperature equilibrium Green's function in the noninteracting limit against exact solutions and in the single-orbital Anderson impurity model against GTEMPO calculations. We also study the zero-temperature non-equilibrium steady state of an impurity coupled to two baths with a voltage bias, obtaining consistent particle currents with existing calculations. The method is ideal for studying steady-state quantum transport, and can be readily used as an efficient real-time impurity solver in the dynamical mean field theory and its non-equilibrium extension.
format Preprint
id arxiv_https___arxiv_org_abs_2403_16700
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Infinite Grassmann Time-Evolving Matrix Product Operator Method in the Steady State
Guo, Chu
Chen, Ruofan
Strongly Correlated Electrons
Quantum Physics
We present an infinite Grassmann time-evolving matrix product operator method for quantum impurity problems, which directly works in the steady state. The method embraces the well-established infinite matrix product state algorithms with the recently developed GTEMPO method, and benefits from both sides: it obtains real-time Green's functions without sampling noises and bath discretization error, it is applicable for any temperature without the sign problem, its computational cost is independent of the transient dynamics and does not scale with the number of baths. We benchmark the method on the finite-temperature equilibrium Green's function in the noninteracting limit against exact solutions and in the single-orbital Anderson impurity model against GTEMPO calculations. We also study the zero-temperature non-equilibrium steady state of an impurity coupled to two baths with a voltage bias, obtaining consistent particle currents with existing calculations. The method is ideal for studying steady-state quantum transport, and can be readily used as an efficient real-time impurity solver in the dynamical mean field theory and its non-equilibrium extension.
title Infinite Grassmann Time-Evolving Matrix Product Operator Method in the Steady State
topic Strongly Correlated Electrons
Quantum Physics
url https://arxiv.org/abs/2403.16700