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arXiv · 0911.5152

Nonadiabatic Dynamics of Ultracold Fermions in Optical Superlattices

Atsushi Yamamoto·Makoto Yamashita·Norio Kawakami
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Abstract

We study the time-dependent dynamical properties of two-component ultracold fermions in a one-dimensional optical superlattice by applying the adaptive time-dependent density matrix renormalization group to a repulsive Hubbard model with an alternating superlattice potential. We clarify how the time evolution of local quantities occurs when the superlattice potential is suddenly changed to a normal one. For a Mott-type insulating state at quarter filling, the time evolution exhibits a profile similar to that expected for bosonic atoms, where correlation effects are less important. On the other hand, for a band-type insulating state at half filling, the strong repulsive interaction induces an unusual pairing of fermions, resulting in some striking properties in time evolution, such as a paired fermion co-tunneling process and the suppression of local spin moments. We further address the effect of a confining potential, which causes spatial confinement of the paired fermions.

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Atsushi Yamamoto, Makoto Yamashita, Norio Kawakami. 2009-11-26. Nonadiabatic Dynamics of Ultracold Fermions in Optical Superlattices. https://doi.org/10.1143/jpsj.78.123002

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