DMFT-QE Symposium: December 16th

Talk 1:

Numerical exploration of high-harmonic generation in strongly correlated systems

Yuta Murakami, RIKEN Center for Emergent Matter Science

High-harmonic generation (HHG) is a fundamental nonlinear optical phenomenon emerging out of strong light-matter couplings. The HHG research was initiated in gases, and more recently extended to semiconductors. In this talk, we further extend this concept to strongly correlated systems, in particular, to Mott insulators. Using powerful numerical techniques such as nonequilibrium dynamical mean-field theory (DMFT), we discuss the basic physical picture of HHG in Mott insulators and its many-body properties absent in semiconductors. Namely, we establish the relation between HHG and the dynamics of doublons and holons and the important role of characteristic spin-charge couplings in Mott insulators.

Talk 2:

Understanding the role of disorder in the nonequilibrium dynamics of a correlated many-particle system

Herbert Fotso, University of Buffalo

We use our recently introduced nonequilibrium DMFT+CPA method to investigate the nonequilibrium dynamics of a disordered interacting system, when it is subjected to an interaction quench. The method combines the capacity, on the one hand of DMFT to treat strongly correlated systems, and the other hand, of CPA (coherent potential approximation) to treat disordered systems, to effectively address the interplay of disorder and interaction for the nonequilibrium system. First, we benchmark the approach on the equilibrium density of states of a system described by the Anderson-Hubbard model with “box” and binary disorder. Next, we evaluate the dynamics and the thermalization of the system when the interaction strength is abruptly changed at a given time, from zero to a finite constant value. We observe that disorder affects the relaxation of the system in a nontrivial manner and we identify different thermalization regimes as a function of disorder and interaction strengths.