https://doi.org/10.1140/epjb/e2016-70215-3
Regular Article
Dynamic shot noise in a quantum dot coupled with Majorana fermions under the perturbation of microwave fields
1 School of Physics, Beijing Institute
of Technology, Beijing
100081, P.R.
China
2 Department of Physics, The University
of Hong Kong, Pokfulam
Road, Hong Kong,
P.R. China
a
e-mail: zhaohonk@bit.edu.cn
Received:
9
April
2016
Received in final form:
25
August
2016
Published online:
24
November
2016
The dynamic properties of a quantum dot (QD) coupled with Majorana fermions under the perturbation of microwave fields (MWFs) have been investigated through the nonequilibrium Green’s function (NGF) technique. The photon-assisted differential conductance, current, shot noise, and Fano factor have been evaluated in the Nambu representation. The normal electron tunneling and Andreev reflections contribute to the transport effectively, and novel conductance peaks appear around each photon-induced side channel. The shot noise is enhanced by increasing the interaction strength of Majorana fermions evidently, while it is suppressed accompanying with peak-valley structures by the MWFs. For the symmetric transmission where the QD energy Ed = 0, terminal current disappears when the source-drain bias eV is removed. For the asymmetric transmission where Ed ≠ 0, there exists nonzero pumping current induced by the applied MWF. The saturate pumping current increases with increasing Ed as eV = 0 and Ed ≠ 0, but the shot noise increases with decreasing Ed. As the coupling energy between the Majorana fermions becomes zero, the Fano factor reaches the robust value F ≈ 0.38 as eV → 0.
Key words: Mesoscopic and Nanoscale Systems
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2016