Production of minimally entangled typical thermal states with the Krylov-space approach

TL;DR

This paper applies the minimally entangled typical thermal states algorithm with a Krylov-space approach to fermionic systems, analyzing thermal properties and correlations, and demonstrating its effectiveness for studying finite-temperature quantum phenomena.

Contribution

The paper introduces a Krylov-space based method for minimally entangled typical thermal states in fermionic systems, enabling efficient finite-temperature simulations.

Findings

Superconducting correlations decay exponentially with distance at low temperatures.

The decay exponents of correlations are proportional to temperature.

Finite-temperature parity correlator is successfully computed.

Abstract

The minimally entangled typical thermal states algorithm is applied to fermionic systems using the Krylov-space approach to evolve the system in imaginary time. The convergence of local observables is studied in a tight-binding system with a site-dependent potential. The temperature dependence of the superconducting correlations of the attractive Hubbard model is analyzed on chains, showing an exponential decay with distance and exponents proportional to the temperature at low temperatures, as expected. In addition, the non-local parity correlator is calculated at finite temperature. Other possible applications of the minimally entangled typical thermal states algorithm to fermionic systems are also discussed.