Predicted giant magnetic moment on non-{n0m} surfaces of d-wave superconductors --- Can it be observed and how?

TL;DR

This paper discusses the potential observability of a giant magnetic moment caused by midgap states on non-{n0m} surfaces of d-wave superconductors, proposing experimental methods to detect it.

Contribution

It demonstrates that the predicted magnetic moment effect is experimentally observable and suggests two specific measurement techniques.

Findings

Magnetic moment can be detected via internal {110} surfaces.

Spin-polarized tunneling can reveal the magnetic moment.

Applying a magnetic field in the [1$ar 1$0] direction is essential.

Abstract

It has been noted previously that the sizable areal density of midgap states which must exist on any non-{n0m} surface of a d-wave superconductor can lead to a giant magnetic moment. Here we show that this effect is observable, and discuss two precise ways to observe it: (i) by directly measuring magnetic moment in a system with a large density of internal {110} surfaces, or (ii) by performing spin-polarized tunneling on a {110} surface. In both cases a sufficiently large magnetic field should be applied in the [1$\bar 1$0] direction.