LOW-TEMPERATURE THERMODYNAMICS OF CHARGED BOSONS IN A RANDOM POTENTIAL AND THE SPECIFIC-HEAT OF LA2-XSRXCUO4 BELOW T-C

We propose a simple analytical form of the partition function for char ged bosons localised in a random potential and derive the consequent t hermodynamics below the superfluid transition temperature. In the low temperature limit, the specific heat C depends on the localisation len gth exponent nu: C is linear for nu less than or equal to 1, but for n u > 1 we obtain C a T-1/nu. This unusual sub-linear temperature depend ence of the specific heat has recently been observed in La2-xSrxCuO4 b elow T-c. (C) 1998 Elsevier Science B.V. All rights reserved.