Electronic States in Half-Filled Correlated System with Alternating Potential

TL;DR

This paper investigates how an alternating potential influences electronic states in a half-filled Hubbard model, revealing conditions for band and Mott insulators through renormalization group analysis.

Contribution

It introduces a detailed analysis of the competition between alternating potential and umklapp scattering in determining insulating states in a one-dimensional Hubbard model.

Findings

Relevance of alternating potential leads to band insulator

Irrelevance results in Mott insulator

Calculated excitation gaps for charge and spin fluctuations

Abstract

The effect of an alternating potential on a one-dimensional half-filled Hubbard model with repulsive interaction has been examined by applying the renormalization group method to the bosonized Hamiltonian. The electronic state, which is determined by the competition between alternating potential and umklapp scattering, is calculated where the relevance and the irrelevance of the alternating potential leads to the band insulator and the Mott insulator respectively. The excitation gaps for charge and spin fluctuations are calculated for both states.