Theory of pairing symmetry inside the Abrikosov vortex core

TL;DR

This paper reveals how the pairing symmetry inside an Abrikosov vortex core depends on vorticity, affecting local density of states, and proposes an STM experiment to detect odd-frequency superconductivity.

Contribution

It introduces the parity change of the Cooper pair wave function at vortex centers depending on vorticity and suggests an experimental method to observe odd-frequency superconductivity.

Findings

Parity of Cooper pair wave function depends on vortex vorticity.

Local density of states varies with frequency parity in vortex cores.

Proposes STM experiment with superconducting tip to detect odd-frequency pairing.

Abstract

We show that the Cooper pair wave function at the center of an Abrikosov vortex with vorticity m has different parity with respect to frequency from that in the bulk if m is an odd number and has the same parity if m is an even number. As a result, in a conventional vortex with m=1, the local density of states at the Fermi energy has a maximum (minimum) at the center of the vortex core in even(odd)-frequency superconductor. We propose a scanning tunneling microscope experiment using a superconducting tip to explore odd-frequency superconductivity.