Many-particle dynamics of bosons and fermions in quasi-one-dimensional flat-band lattices
M. Hyrkäs, V. Apaja, and M. Manninen
Accepted
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 Newtons 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.