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arXiv · 1803.02071

Coupled charge and spin dynamics in a photo-excited Mott insulator

Nikolaj Bittner·Denis Golež·Hugo U. R. Strand·Martin Eckstein·Philipp Werner
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Abstract

Using a nonequilibrium implementation of the extended dynamical mean field theory (EDMFT) we simulate the relaxation after photo excitation in a strongly correlated electron system with antiferromagnetic spin interactions. We consider the $t$-$J$ model and focus on the interplay between the charge- and spin-dynamics in different excitation and doping regimes. The appearance of string states after a weak photo excitation manifests itself in a nontrivial scaling of the relaxation time with the exchange coupling and leads to a correlated oscillatory evolution of the kinetic energy and spin-spin correlation function. A strong excitation of the system, on the other hand, suppresses the spin correlations and results in a relaxation that is controlled by hole scattering. We discuss the possibility of detecting string states in optical and cold atom experiments.

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Nikolaj Bittner, Denis Golež, Hugo U. R. Strand, Martin Eckstein, Philipp Werner. 2018-03-06. Coupled charge and spin dynamics in a photo-excited Mott insulator. https://doi.org/10.1103/physrevb.97.235125

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