Nonlinear ac conductivity of one-dimensional Mott insulators

TL;DR

This paper presents a semiclassical approach to calculate the nonlinear ac conductivity in one-dimensional Mott insulators, revealing insights into multi-photon absorption processes and comparing with quantum calculations.

Contribution

It introduces a combined RG and instanton semiclassical method to analyze nonlinear ac conductivity in 1d Mott insulators, bridging classical and quantum perspectives.

Findings

Good agreement between semiclassical and quantum multi-photon absorption results for large photon numbers.

Semiclassical calculations effectively describe nonlinear charge transport in 1d Mott insulators.

Multi-photon absorption is a key mechanism in the nonlinear ac response of these systems.

Abstract

We discuss a semiclassical calculation of low energy charge transport in one-dimensional (1d) insulators with a focus on Mott insulators, whose charge degrees of freedom are gapped due to the combination of short range interactions and a periodic lattice potential. Combining RG and instanton methods, we calculate the nonlinear ac conductivity and interpret the result in terms of multi-photon absorption. We compare the result of the semiclassical calculation for interacting systems to a perturbative, fully quantum mechanical calculation of multi-photon absorption in a 1d band insulator and find good agreement when the number of simultaneously absorbed photons is large.