Low-temperature heat capacity of the mixed state of superconductors with anisotropic pairing

Abstract

It is shown that in superconductors with anisotropic pairing the exponent of the power-law magnetic-field dependence of the low-temperature heat capacity of the mixed state depends strongly on the multiplicities of the zeros of the superconducting order parameter. As a result, an experimental determination of the corresponding power-law exponent makes it possible to judge not only the presence of zeros in the order parameter but also the multiplicities of these zeros. An expression is obtained for the spatially nonuniform quasiparticle density of states at low energies.