Nonlinear Optical Response Functions of Mott Insulators Based on Dynamical Mean Field Approximation

TL;DR

This paper studies the nonlinear optical responses of Mott insulators using dynamical mean field theory, revealing unique behaviors and scaling relations that align with experimental observations.

Contribution

It introduces a comprehensive analysis of nonlinear optical susceptibilities in Mott insulators, emphasizing the role of all interaction types with external fields.

Findings

Direct transition terms dominate TPA and THG spectra.

Different coupling types show distinct behaviors from semiconductors.

Scaling relations connect Coulomb interaction strength to spectral features.

Abstract

We investigate the nonlinear optical susceptibilities of Mott insulators with the dynamical mean field approximation. The two-photon absorption (TPA) and the third-harmonic generation (THG) spectra are calculated, and the classification by the types of coupling to external fields shows different behavior from conventional semiconductors. The direct transition terms are predominant both in the TPA and THG spectra, and the importance of taking all types of interaction with the external field into account is illustrated in connection with the THG spectrum and dcKerr effect. The dependence of the TPA and THG spectra on the Coulomb interaction indicate a scaling relation. We apply this relation to the quantitative evaluation and obtain results comparable to those of experiments.