Observation of the Non-linear Meissner Effect
Superconductivity
2025-04-29 v3
Abstract
A long-standing theoretical prediction is that in clean, nodal unconventional superconductors the magnetic penetration depth , at zero temperature, varies linearly with magnetic field. This non-linear Meissner effect is an equally important manifestation of the nodal state as the well studied linear-in- dependence of , but has never been convincingly experimentally observed. Here we present measurements of the nodal superconductors CeCoIn and LaFePO which clearly show this non-linear Meissner effect. We further show how the effect of a small dc magnetic field on can be used to distinguish gap nodes from non-nodal deep gap minima. Our measurements of KFeAs suggest that this material has such a non-nodal state.
Keywords
Cite
@article{arxiv.2008.04050,
title = {Observation of the Non-linear Meissner Effect},
author = {J. A. Wilcox and M. J. Grant and L. Malone and C. Putzke and D. Kaczorowski and T. Wolf and F. Hardy and C. Meingast and J. G. Analytis and J. -H. Chu and I. R. Fisher and A. Carrington},
journal= {arXiv preprint arXiv:2008.04050},
year = {2025}
}