Tunnelling conductance of $d+ip$-wave superconductor

TL;DR

This paper theoretically studies the tunneling conductance of a $d+ip$-wave superconductor, revealing the robustness of the zero-bias peak against certain surface orders and suggesting the feasibility of a spin-triplet $p$-wave surface order.

Contribution

It provides a self-consistent analysis of tunneling conductance in $d+ip$-wave superconductors using quasiclassical theory, highlighting the stability of zero-bias peaks and proposing the existence of a spin-triplet $p$-wave surface order.

Findings

Zero-bias peak is robust against spin-triplet $p$-wave surface order.

Zero-bias peak is fragile against spin-singlet $s$-wave order.

Spin-triplet $p$-wave surface order is feasible based on numerical and experimental comparison.

Abstract

We theoretically investigate the tunneling conductance of the $d+ip$-wave superconductor which is recently proposed to be realised at the (110) surface of a high-$T_c$ cuprate superconductor. Utilizing the quasiclassical Eilenberger theory, we obtain the self-consistent pair potentials and the differential conductance of the normal-metal/$d+ip$-wave superconductor junction. We demonstrate that the zero-bias peak of a $d$-wave superconductor is robust against the spin-triplet $p$-wave surface subdominant order even though it is fragile against the spin-singlet $s$-wave one. Comparing our numerical results and the experimental results, we conclude the spin-triplet $p$-wave surface subdominant order is feasible.