Searching for zeroes: unconventional superconductors in a magnetic field

TL;DR

This paper reviews a microscopic approach to understanding how the specific heat anisotropy in unconventional superconductors varies with magnetic field orientation, temperature, and material properties.

Contribution

It introduces a comprehensive method that considers vortex scattering and energy shifts to predict specific heat behavior in rotated magnetic fields.

Findings

Specific heat minima or maxima depend on field orientation and temperature.

Paramagnetic limiting and Fermi surface shape influence anisotropy inversion.

The approach explains experimental observations of anisotropy inversion in superconductors.

Abstract

We review the results of the microscopic approach to the calculation of the anisotropy in the specific heat in unconventional superconductors under rotated field. Treating vortex scattering on equal footing with the energy shift we find that the electronic specific heat may have minima or maxima when the field is aligned with the nodes, depending on the temperature and field range. We discuss the influence of the paramagnetic limiting and Fermi surface shape on the location of the inversion line.