Piezoelectric effect and diode effect in anapole and monopole superconductors

TL;DR

This paper predicts the occurrence of piezoelectric and diode effects in anapole and monopole superconductors, which lack certain symmetries, proposing these effects as probes for exotic superconducting phases.

Contribution

It introduces the prediction of superconducting piezoelectric and diode effects in $PT$-symmetric anapole and monopole superconductors, linking these phenomena to finite-$q$ pairing and quantum geometry.

Findings

Predicted superconducting piezoelectric effect in specific superconducting states.

Predicted superconducting diode effect as a signature of exotic phases.

Linked these effects to asymmetric Bogoliubov spectra and quantum geometry.

Abstract

Superconductors lacking both inversion symmetry and time-reversal symmetry have been attracting much attention as a platform for exotic superconducting phases and anomalous phenomena, including the superconducting diode effect. Recent studies revealed intrinsic phases with this symmetry, named anapole superconductivity and monopole superconductivity, which are $PT$-symmetric superconducting states with and without Cooper pairs' total momentum, respectively. To explore characteristic phenomena in these states, we calculate and predict the superconducting piezoelectric effect and superconducting diode effect. A close relationship with the finite-$q$ pairing, asymmetric Bogoliubov spectrum, and quantum geometry is discussed. This study reveals the piezoelectric and diode effects as potential probes to elucidate exotic superconducting phases.