Multidimensional coherent spectroscopy of correlated lattice systems

TL;DR

This paper demonstrates how multidimensional coherent spectroscopy (MDCS) can be used to probe and understand the complex nonequilibrium dynamics and excitation pathways in correlated lattice systems using advanced theoretical models.

Contribution

It introduces a systematic theoretical framework combining Keldysh contour and dynamical mean field theory to interpret MDCS signals in correlated electron materials.

Findings

MDCS effectively reveals excitation pathways in correlated solids.

The technique provides detailed insights into the evolution of photo-excited states.

MDCS can diagnose coherent processes in complex materials.

Abstract

Multidimensional coherent spectroscopy (MDCS) has been established in quantum chemistry as a powerful tool for studying the nonlinear response and nonequilibrium dynamics of molecular systems. More recently, the technique has also been applied to correlated electron materials, where the interplay of localized and itinerant states makes the interpretation of the spectra more challenging. Here we use the Keldysh contour representation of effective models and nonequilibrium dynamical mean field theory to systematically study the MDCS signals of prototypical correlated lattice systems. By analyzing the current induced by sequences of ultrashort laser pulses we demonstrate the usefulness of MDCS as a diagnostic tool for excitation pathways and coherent processes in correlated solids. We also show that this technique allows to extract detailed information on the nature and evolution of photo-excited nonequilibrium states.