Vacancy-assisted superfluid drag
Abstract
We study superfluid drag in the two-component Bose-Hubbard model with infinitely strong repulsive interactions. In this system, all transport is mediated by the motion of empty sites, or ``holes", and it is hard to move one component without moving the other. We demonstrate, with a combination of analytic and numeric techniques, that the motion of holes leads to strong dissipationless coupling between currents in the two components. This behavior is attributable to polaronic correlations that emerge in the presence of spin currents, which can be observed in experiments. We derive a closed-form expression for the coupling on various lattices in arbitrary spatial dimensions, which we verify through numerical simulations on two dimensional lattices.
Cite
@article{arxiv.2502.00542,
title = {Vacancy-assisted superfluid drag},
author = {Thomas G. Kiely and Chao Zhang and Erich J. Mueller},
journal= {arXiv preprint arXiv:2502.00542},
year = {2025}
}
Comments
9 pages, 5 figures