arXiv:1201.0468 · Physical Review A

Many-particle dynamics of bosons and fermions in quasi-one-dimensional flat-band lattices

M J Hyrkäs, V. Apaja, M. Manninen

Published Feb 15, 2013• 88 citations

Abstract

The difference between boson and fermion dynamics in quasi-one-dimensional lattices is studied by calculating the persistent current in small quantum rings and by exact simulations of the time evolution of the many-particle state in two cases: expansion of a localized cloud and collisions in a Newton's cradle. We consider three different lattices which in the tight-binding model exhibit flat bands. The physical realization is considered to be an optical lattice with bosonic or fermionic atoms. The atoms are assumed to interact with a repulsive short-range interaction. The different statistics of bosons and fermions lead to different dynamics. Spinless fermions are easily trapped in the flat-band states due to the Pauli exclusion principle, which prevents them from interacting, while bosons are able to push each other out from the flat-band states.

DOI: 10.1103/physreva.87.023614

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