Dirac quasiparticles in the mixed state - art. no. 014502

Energies and wave functions are calculated for d-wave quasiparticles in the mixed state using the formalism of Franz and Tesanovic for the low-lying e nergy levels. The accuracy of the plane-wave expansion is explored by compa ring approximate to exact results for a simplified one-dimensional problem, and the convergence of the plane-wave expansion to the two-dimensional cas e is studied. The results are used to calculate the low-energy tunneling de nsity of states and the low-temperature specific heat, and these theoretica l results are compared to semiclassical treatments and to the available dat a. Implications for the muon spin resonance measurements of vortex core siz e are also discussed.