Charge transport properties of the Majorana zero mode induced noncollinear spin selective Andreev reflection

TL;DR

This paper investigates how the charge transport and noise characteristics of spin-selective Andreev reflection can be used to detect Majorana zero modes, considering the effects of excited states and spin polarization angles.

Contribution

It introduces a comprehensive analysis of the influence of excited states and spin polarization angles on charge transport and noise in SSAR involving Majorana zero modes.

Findings

First excited states affect conductance peaks when spin polarizations are noncollinear.

Shot noise power and Fano factor depend on the angle between spin polarizations.

Transport properties can serve as additional signatures for detecting Majorana zero modes.

Abstract

We study the charge transport of the spin-selective Andreev reflection(SSAR) effect between a spin polarized scanning tunneling microscope(STM) tip and a Majorana zero mode(MZM). Considering both the MZM and the excited states, we calculate the conductance and the shot noise power of the noncollinear SSAR using scattering theory. We find the influence of first excited states cannot be avoided when the spin polarization direction of the STM tip and the MZM are not collinear. In this case, the first excited states give rise to inside peaks and change the conductance peak value at zero energy. Moreover, we numerically calculate the shot noise power and the Fano factor of the SSAR effect. Our calculation shows that the shot noise power and the Fano factor are related to the angle between the spin polarization direction of the STM tip and that of the MZM. These transport properties of the SSAR effect provide additional characteristics to detect the MZM via SSAR.