Low temperature thermodynamics of charged bosons in a random potential and the specific heat of La_{2-x}Sr_{x}CuO_{4} below Tc

TL;DR

This paper derives a simple analytical model for the thermodynamics of charged bosons in a random potential, explaining the unusual specific heat behavior observed in La_{2-x}Sr_{x}CuO_{4} below its critical temperature.

Contribution

It introduces an analytical form of the partition function for localized charged bosons and links the specific heat's temperature dependence to the localization length exponent.

Findings

Specific heat is linear for localization exponent nu<1

For nu>1, specific heat scales as T^{1/nu}

Model explains experimental observations in La_{2-x}Sr_{x}CuO_{4}

Abstract

We propose a simple analytical form of the partition function for charged bosons localised in a random potential and derive the consequent thermodynamics below the superfluid transition temperature. In the low temperature limit, the specific heat, C, depends on the localisation length exponent nu: C is linear for nu<1, but for nu>1 we find C proportional to T^{1/nu}. This unusual sub-linear temperature dependence of the specific heat has recently been observed in La_{2-x}Sr_{x}CuO_{4} below Tc.