Shear Modulus Anomaly of Unconventional Superconductor in a Symmetry Breaking Field

TL;DR

This paper theoretically investigates the shear modulus anomaly in unconventional superconductors with multicomponent order parameters under symmetry-breaking fields, predicting experimental signatures for chiral and nematic states, including a notable vanishing of $C_{66}$.

Contribution

It introduces a Ginzburg-Landau based theoretical framework to analyze shear modulus anomalies in split superconducting transitions caused by symmetry-breaking fields.

Findings

Prediction of shear modulus anomalies in chiral and nematic superconductors.

Identification of vanishing $C_{66}$ at the nematic transition.

Guidance for future experimental detection of unconventional superconducting states.

Abstract

Using Ginzburg-Landau formalism, we theoretically study the isothermal shear modulus anomaly of an unconventional superconductor with a multicomponent order parameter, when the superconducting transition is split by a symmetry-breaking field. Experimental signatures are proposed for both chiral and nematic superconductors. Particularly striking is the vanishing of $C_{66}$ across the lower transition to a nematic superconducting state. Our findings can guide future experiments and shed new lights on materials such as Sr$_2$RuO$_4$ and $M_x$Bi$_2$Se$_3$.