Singularity of the vortex density of states in d-wave superconductors

In d-wave superconductors, the electronic density of states (DOS) induced by a vortex exhibits a divergence at low energies: N _vortex(E) ∼1/|E|. This divergence is the result of gap nodes in the spectrum of excitation outside the vortex core. The heat capacity in two regimes, T ²/T _c ² ≫ B/B _c 2 and T ²/T _c ² ≪ B/B _c 2, is discussed. Pis’ma Zh. éksp. Teor. Fiz. 64, No. 9, 641–645 (10 November 1996) Published in English in the original Russian journal. Edited by Steve Torstveit.