Burovski, Evgeny and Orso, Giuliano and Jolicoeur, Thierry (2009) Mutiparticle Composites in Density-Imbalanced Quantum Fluids. Physical review letters, 103 (21): 215301. ISSN 1079-7114
Abstract
We consider two-component one-dimensional quantum gases with a density imbalance. While generically such fluids are two-component Luttinger liquids, we show that if the ratio of the densities is a rational number, p/q, and mass asymmetry between components is sufficiently strong, one of the two eigenmodes acquires a gap. The gapped phase corresponds to (algebraic) ordering of (p+q)-particle composites. In particular, for attractive mixtures, this implies that the superconducting correlations are destroyed. We illustrate our predictions by numerical simulations of the fermionic Hubbard model with hopping asymmetry.