Low temperature thermodynamics of charged bosons in a random potential and the specific heat of La2-xSrxCuO4 below Tc

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 less than or equal to 1, but for nu > 1 we obtain C a T-1/nu. This unusual sub-linear temperature dependence of the specific heat has recently been observed in La2-xSrxCuO4 below T-c. (C) 1998 Elsevier Science B.V. All rights reserved.