Influence of Majorana doublet on transport through a quantum dot system with ferromagnetic leads

• Influence of Majorana doublet on transport through a dot with ferromagnetic leads is studied.
• When the dot couples to Majorana doublet, zero-bias conductance is always equal to e2/h.
• If Majorana singlet arises, zero-bias conductance is sensitive to structural parameters.
• This work provides ideas for detecting the Majorana doublet via a quantum dot setup.

We investigate the electron transport through a quantum dot connected with two ferromagnetic leads, by coupling one Majorana doublet laterally to the quantum dot. It is found that Majorana doublet keeps the value of zero-bias conductance to be independent of the shift of structural parameters, including dot level, relative lead-magnetization direction, and magnetic field on the dot. Even in the cases of asymmetric dot-lead couplings, the zero-bias conductance is weakly dependent on the relative lead-magnetization direction. On the other hand, when Majorana doublet is replaced by Majorana singlet, the zero-bias conductance value becomes sensitive to the structural parameters. Via analyzing the respective particle motion processes, the different influences of Majorana doublet and singlet are explained. We believe that this work can be helpful for understanding the peculiar properties of Majorana doublet.