De Haas-van Alphen oscillations in superconducting states as a probe of gap anisotropy

Abstract

It is argued that the de Haas-van Alphen (dHvA) oscillations become detectable in the superconducting states even in a case exp( −2πΔ ℏω c )⪡1 , provided that the gap vanishes at points or along lines on the Fermi surface and that the upper critical field B c2 is high enough for dHvA oscillations to be observed. This gives us a possibility to probe the gap anisotropy by dHvA measurements.