Effect of uniaxially anisotropic Fermi surface on the quasiparticle scattering inside a vortex core in unconventional superconductors

We theoretically study the dependence of the quasiparticle (QP) scattering rate $varGamma$ on the uniaxial anisotropy of a Fermi surface with changing the magnetic field angle $alpha_{rm M}$. We consider the QP scattering due to the non-magnetic impurities inside a single vortex core. The field-angle dependence of the quasiparticle scattering rate $varGamma(alpha_{rm M})$ is sensitive to the sign-change of the pair potential. We show that with increasing the two dimensionality of the system, $varGamma(alpha_{rm M})$ reflects more clearly whether there is the sign-change in the pair potential.