Impurity resonance states in noncentrosymmetric superconductor $CePt_{3}Si$: a probe for Cooper-pairing symmetry

TL;DR

This paper theoretically investigates impurity-induced resonance states in noncentrosymmetric superconductors like CePt3Si, revealing how local density of states features can help identify the pairing symmetry and gap structure.

Contribution

It provides a detailed analysis of impurity resonance states for coexisting s- and p-wave pairing, offering a method to probe superconducting gap symmetry via STM.

Findings

Impurity resonances appear in the local density of states due to nodal gap structure.

Evolution of LDOS differs between isotropic and anisotropic pairing states.

STM can distinguish different superconducting gap structures in non-centrosymmetric superconductors.

Abstract

Motivated by the recent discovery of noncentrosymmetric superconductors, such as $CePt_{3}Si$, $CeRhSi_{3}$ and $CeIrSi_{3}$, we investigate theoretically the impurity resonance states with coexisting $s$- and p-wave pairing symmetries. Due to the nodal structure of the gap function, we find single nonmagnetic impurity-induced resonances appearing in the local density of state (LDOS). In particular, we analyze the evolution of the local density of states for coexisting isotropic s-wave and p-wave superconducting states and compare with that of anisotropic s-wave and p-wave symmetries of the superconducting gap. Our results show that the scanning tunneling microscopy can shed light on the particular structure of the superconducting gap in non-centrosymmetric superconductors.