Shot noise and its spectral decomposition in hybrid system of double quantum dots-topological superconductor

The shot noise of electron transport processes in a hybrid system of double quantum dots coupled to topological superconducting nanowire is studied. There may be various coherent tunneling mechanisms in the system, and we investigate the shot noise in four cases of mixed systems, when the Majorana bound state and the Poorman's Majorana bound state do not exist, and when they exist respectively and simultaneously. It is found that two coherent tunneling mechanisms corresponding to the two bound states result in significant enhancement of the low and zero frequency shot noise, but affect the depth and dynamics behavior of the characteristic valley of shot noise significantly differently. It can provide evidence to distinguish Majorana bound states and Poorman's Majorana bound state. In addition, the shot noise spectral is decomposed. Studying the components, one finds that system-environment interactions, as well as single electron transport, competes with electron coherent tunneling. This paper contributes to a deeper understanding of the nature of Majorana bound states.