Shot noise in Majorana bound state modulated double-quantum-dot interferometer connected to normal and superconductive terminals

Abstract

The mesoscopic transport through double-quantum-dot (DQD) Aharonov–Bohm (AB) interferometer coupled with Majorana bound states (MBSs), as well as normal and superconductive terminals has been investigated. The current, shot noise and Fano factor have been calculated versus AB phase and source-drain bias (eV). The calculated Fano factor F displays explicit features of MBSs through its AB oscillations and source-drain bias characteristics. The sinusoid and multi-peak \(4\pi \)-periodic oscillations are exhibited versus AB phase due to modifying the DQD levels and coupling constants. Significant peak-valley structures of Fano factor contributed by Andreev reflections and MBSs exhibit in small source-drain bias region. The Fano factor is suppressed by increasing the coupling strengths \(\lambda _i\) (\( i=1,2\)) of MBSs with DQD, while it is enhanced by increasing the coupling energy (\(\varepsilon _{M}\)) between two MBSs. For the case as \(\varepsilon _{M}\ne 0\), a specific value around \(F\approx 2\) is reached for different \(\lambda _i\) as \(eV\rightarrow 0\). While for the case as \(\varepsilon _{M}=0\), small values around \(F\approx 0\) are presented due to setting different coupling constants \(\lambda _i\) as \(eV\rightarrow 0\).