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

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.