Tunnelling conductance of $d+ip$-wave superconductor

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.