Abstract
We investigate how fast and how effective photocarrier excitation can modify the exchange interaction in the prototype Mott-Hubbard insulator. We demonstrate an ultrafast quenching of both by evaluating exchange integrals from a time-dependent response formalism and by explicitly simulating laser-induced spin precession in an antiferromagnet that is canted by an external magnetic field. In both cases, the electron dynamics is obtained from nonequilibrium dynamical mean-field theory. We find that the modified emerges already within a few electron hopping times after the pulse, with a reduction that is comparable to the effect of chemical doping.
- Received 20 January 2014
DOI:https://doi.org/10.1103/PhysRevLett.113.057201
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