Kramer-Pesch approximation for analyzing field-angle-resolved measurements made in unconventional superconductors: a calculation of the zero-energy density of states.
By measuring the angular-oscillations behavior of the heat capacity with respect to the applied field direction, one can detect the details of the gap structure. We introduce the Kramer-Pesch approximation as a new method to analyze the field-angle-dependent experiments, which improves the previous Doppler-shift technique. We show that the Fermi-surface anisotropy is an indispensable factor for identifying the superconducting gap symmetry.
Department of Physics, University of Tokyo, Tokyo 113-0033, Japan.
Yuki
Y
Nagai
Nobuhiko
N
Hayashi