Temperature-induced gap formation in dynamic correlation functions of the one-dimensional Kondo insulator --- Finite-temperature density-matrix renormalization-group study ---

TL;DR

This paper introduces a new computational method combining finite-temperature density-matrix renormalization-group and maximum entropy techniques to analyze dynamic correlation functions in one-dimensional Kondo insulators, revealing temperature-dependent gap formation.

Contribution

It presents a novel approach for calculating dynamic quantities in 1D many-body systems at finite temperature, specifically applied to Kondo insulators.

Findings

Excitation gaps open as temperature decreases.

Gaps vary across different channels.

Spectral changes occur around the spin gap temperature.

Abstract

Combination of the finite-temperature density-matrix renormalization-group and the maximum entropy presents a new method to calculate dynamic quantities of one-dimensional many-body systems. In the present paper, density of states, local dynamic spin and charge correlation functions of the one-dimensional Kondo insulator are discussed. Excitation gaps open with decreasing temperature and the gaps take different values depending on channels. The excitation spectra change qualitatively around the characteristic temperature corresponding to the spin gap which is the lowest energy scale of the Kondo insulator.