Two-body correlations and the superfluid fraction for nonuniform systems
Abstract
We extend the one-body phase function upper bound on the superfluid fraction in a periodic solid (a spatially ordered supersolid) to include two-body phase correlations. The one-body current density is no longer proportional to the gradient of the one-body phase times the one-body density, but rather it depends also on two-body correlation functions. The equations that simultaneously determine the one-body and two-body phase functions require a knowledge of one-, two-, and three-body correlation functions. The approach can also be extended to disordered solids. Fluids, with two-body densities and two-body phase functions that are translationally invariant, cannot take advantage of this additional degree of freedom to lower their energy.
Cite
@article{arxiv.cond-mat/0612464,
title = {Two-body correlations and the superfluid fraction for nonuniform systems},
author = {Wayne M. Saslow and Davide E. Galli and Luciano Reatto},
journal= {arXiv preprint arXiv:cond-mat/0612464},
year = {2009}
}
Comments
13 pages