Magnetotunneling spectroscopy as a probe for pairing symmetry determination in quasi-2D anisotropic superconductors

TL;DR

This paper proposes a tunneling spectroscopy method with in-plane rotating magnetic fields to determine pairing symmetry in quasi-2D anisotropic superconductors, analyzing how surface density of states oscillates with field orientation.

Contribution

It introduces a novel spectroscopic technique using magnetic field rotation to identify pairing symmetry, applicable to high-$T_c$ cuprates and organic superconductors.

Findings

Surface density of states oscillates with magnetic field rotation.

Minimum density of states occurs when field aligns with node directions.

Oscillation amplitude depends on Fermi surface shape.

Abstract

As a probe to determine the pairing symmetry of quasi-two-dimensional anisotropic superconductors, we propose tunneling spectroscopy in the presence of magnetic field, where the magnetic field is parallel to the two dimensional planes and rotated. As a case study, we apply this idea to the models of high-$T_{C}$ cuprates and organic superconductors $\kappa$-(ET)$_2X$. The surface density of states at the Fermi energy exhibits a characteristic oscillation upon rotating the direction of the magnetic field due to the Doppler shift of the energy of quasiparticles. The surface density of states has a minimum when the applied magnetic field is parallel to the node direction of the pair potential independent of the detailed shape of the Fermi surface. The amplitude of the oscillation is sensitively affected by the shape of Fermi surface.