= Nodal quasiparticle density of states in a two-dimensional d-wave superconductor
{title2=$g_{\rm qp}(E)/\mathcal A=4E/(\pi\alpha\beta)$}
For four equivalent nodes, two spin <quasiparticles> and local dispersion $E^2=\alpha^2q_1^2+\beta^2q_2^2$, one node encloses momentum area $\pi E^2/(\alpha\beta)$. Counting states with measure $d^2q/(2\pi)^2$ gives the displayed positive-excitation density. The associated clean low-temperature <heat capacity> is $C/\mathcal A=18\zeta(3)k_B^3T^2/(\pi\alpha\beta)$. Electron-addition spectral density alone has a different count because its coherence weights do not count all particle and hole thermal excitations.
Back to article page
