Accurate simulation and thermal tuning by temperature-adaptive boundary interactions on quantum many-body systems

TL;DR

This paper introduces a temperature-adaptive entanglement simulator (TAES) that efficiently models the thermodynamics of 1D many-body quantum systems by optimizing boundary interactions, surpassing existing methods in accuracy.

Contribution

The work presents a novel boundary interaction optimization approach for simulating quantum thermodynamics, enabling accurate and tunable modeling of many-body systems at finite temperatures.

Findings

TAES outperforms existing finite-temperature tensor network methods.

Boundary couplings can be tuned to mimic temperature effects.

Bulk entropy behavior aligns with temperature tuning.

Abstract

Constructing quantum Hamiltonians for simulating and controlling the exotic physics of many-body systems belongs to the most important topics of condensed matter physics and quantum technologies. The main challenge that hinders the future investigations is the extremely high complexity for either their numerical simulations or experimental realizations. In this work, we propose the temperature-adaptive entanglement simulator (TAES) that mimics and tunes the thermodynamics of the one-dimensional (1D) many-body system by embedding a small-size model in an entanglement bath. The entanglement bath is described by the interactions located at the boundaries of the small-size model, whose coupling constants are optimized by means of differentiable tensor network at target temperatures. With the benchmark on 1D spin chains, TAES surpasses the state-of-the-art accuracy compared with the existing finite-temperature approaches such as linearized and differential tensor renormalization group algorithms. By tuning the couplings of the entanglement bath with the temperature fixed, the bulk entropy exhibits similar behavior compared to that obtained by tuning the temperature. Our work provides novel opportunities of engineering the distribution of fluctuations and mimicking the non-equilibrium phenomena in a uniform temperature within the canonical ensemble framework using the optimized boundary interactions.