Boson and fermion dynamics in quasi-one-dimensional flat band lattices

TL;DR

This paper investigates the contrasting dynamics of bosons and fermions in quasi-one-dimensional flat band lattices through exact simulations and persistent current calculations, revealing how quantum statistics influence particle behavior.

Contribution

It provides a detailed comparison of boson and fermion dynamics in flat band lattices, highlighting the effects of quantum statistics on particle trapping and interactions.

Findings

Fermions are trapped in flat bands due to Pauli exclusion.

Bosons can push each other out of flat band states.

Different particle statistics lead to distinct dynamical behaviors.

Abstract

The difference between boson and fermion dynamics in quasi-one-dimensional lattices is studied with exact simulations of particle motion and by calculating the persistent current in small quantum rings. 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 causes different dynamics. Spinless fermions are easily trapped in the flat band states due to the Pauli exclusion principle, which prevents them from interacting, while boson are able to push each other out from the flat band states.