Nonequilibrium dynamics of multiorbital correlated electron system under time-depending electric field

時間変動する電場の下での多軌道強相関電子系の非平衡ダイナミクス

大西 弘明  

Onishi, Hiroaki

To clarify a role of orbital degrees of freedom in the response to an external field, we investigate the real-time dynamics under applied electric fields in a one-dimensional orbital degenerate Hubbard model, by exploiting numerical techniques. Let us here consider a chain along the axis with -orbital degrees of freedom on each site and one electron per site. In the ground state, the itinerant orbital is singly occupied and the localized orbital is empty, while the spin state exhibits antiferromagnetic correlations. After an oscillating electric field is turned on, holon-doublon pairs are created. As the time evolves, the ferro-orbital state is deformed due to the pair-hopping process that is characteristic of multi-orbital systems. Regarding the spin state, we observe the suppression of the antiferromagnetic correlations. We will also address the other filling case.