Onset of superfluidity in random media

Abstract

The zero-temperature superfluid onset transition for a system of repulsively interacting bosons in a random potential is studied. The associated quantum critical behavior is characterized in d dimensions by exponents ν≥2/d, η, and a dynamic exponent z. Static and dynamic scaling laws are derived: Some measureable exponents, such as z=d, are predicted exactly. Applications to experiments on ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ absorbed in porous media are discussed.