Probing the existence and dynamics of Majorana fermion via transport through a quantum dot

Abstract

We consider an experimentally feasible setup to demonstrate the existence and coherent dynamics of a Majorana fermion. The setup consists of a quantum dot and a tunnel-coupled semiconductor nanowire which is anticipated to support Majorana excitations under some conditions. For transport under finite bias voltage, we find that a subtraction of the source and drain currents can expose the essential features of the Majorana fermion, including the zero-mode nature by gate-voltage modulating the dot level. Moreover, the Majorana coherent oscillation dynamics between the nanowire and the quantum dot is revealed in the shot noise, via a spectral dip together with a pronounced zero-frequency noise enhancement effect. Important parameters, e.g., the Majorana's mutual interaction and its coupling to the quantum dot, can be extracted by using the derived analytic results.