Microwave conductivity experiments can directly measure the quasiparticle scattering rate in the superconducting state. We show that this, combined with knowledge of the Fermi surface geometry, allows one to distinguish between closely related superconducting order parameters, e.g., dx2−y2 and dxy superconductivity. We benchmark this method on YBa2Cu3O7−δ and, unsurprisingly, confirm that this is a dx2−y2 superconductor. We then apply our method to κ-(BEDT-TTF)2Cu[N(CN)2]Br, which we discover is a dxy superconductor.
@article{arxiv.1902.02030,
title = {Microwave Conductivity Distinguishes Between Different d-wave States: Umklapp Scattering in Unconventional Superconductors},
author = {D. C. Cavanagh and B. J. Powell},
journal= {arXiv preprint arXiv:1902.02030},
year = {2019}
}