The effect of an in-plane magnetic field on the interlayer transport of quasiparticles in layered superconductors

TL;DR

This paper investigates how an in-plane magnetic field affects the interlayer quasiparticle transport in layered superconductors, revealing that angle-dependent measurements can map the superconducting gap's nodal structure.

Contribution

It demonstrates that the quasiparticle c-axis conductivity's dependence on magnetic field orientation can be used to identify gap nodes in layered superconductors.

Findings

Interlayer conductivity varies strongly with magnetic field angle at low temperatures.

Angle-dependent magnetoresistance measurements can reveal the momentum dependence of the superconducting gap.

Highly anisotropic layered superconductors are ideal for probing gap nodes.

Abstract

We consider the quasiparticle c-axis conductivity in highly anisotropic layered compounds in the presence of the magnetic field parallel to the layers. We show that at low temperatures the quasiparticle interlayer conductivity depends strongly on the orientation of the in-plane magnetic field if the excitation gap has nodes on the Fermi surface. Thus measurements of the angle-dependent c-axis (out-of-plane) magnetoresistance, as a function of the orientation of the magnetic field in the layers, provide information on the momentum dependence of the superconducting gap (or pseudogap) on the Fermi surface. Clean and highly anisotropic layered superconductors seem to be the best candidates for probing the existence and location of the nodes on the Fermi surface.