Study on the tunneling spectroscopy of $N-pS$ junction and $N-hS$ junction

摘要

We study the complete tunneling spectroscopy of a normal metal/$p$-wavesuperconductor junction ($N-pS$) and normal metal/heterostructuresuperconductor junction ($N-hS$) by Blonder-Tinkham-Klapwijk (BTK) method. Wefind that, for $p$-wave superconductor with non-trivial topology, there existsa quantized zero-bias conductance peak stably, for heterostructuresuperconductor with non-trivial topology, the emerging zero-bias conductancepeak is non-quantized and usually has a considerable gap to the quantizedvalue. Furthermore, it is sensitive to parameters, especially to spin-orbitcoupling and the $s$-wave pairing potential. Results obtained suggest that theobservation of a small zero-bias conductance peak, instead of a quantizedzero-bias conductance peak, in current tunneling experiments can be a naturalresult if the spin-orbit coupling turns out to be several times smaller thanthe reported one. Results obtained also suggest that both a stronger spin-orbitcoupling and proximity $s$-wave superconductor with relative weaker pairingpotential can produce a much more striking zero-bias conductance peak (comparedto the experiments), even an almost quantized one. As $s$-wave superconductorsare common in nature, the prediction can be verified within current experimentability.