Majorana States in Presence of Electron Interactions: Spinful Fractional Josephson Junction with a Quantum Dot

P. Stefański Institute of Molecular Physics of the Polish Academy of Sciences, ul. Smoluchowskiego 17, 60-179 Poznań, Poland

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We consider a fractional Josephson junction mediated by a quantum dot in which the Zeeman field arising from the magnetic fields driving left and right wires into topological phase can be tuned. Both fields, forming an angle Θp, can be rotated in the common plane perpendicular to the spin-orbit field in the wires. For Θp=0 the dot can be regarded as effectively non-interacting due to the large Zeeman splitting, whereas for Θp ≤sssimπ electron interactions are switched on the dot, affecting Majorana states. The tunnel electrode, weakly coupled to the dot from the top, allows to probe their density of states via conductance measurement. We show that electron interactions renormalize Majorana peak and introduce characteristic asymmetry in the gate voltage dependence of the transverse zero-bias conductance through the dot.

DOI: 10.12693/APhysPolA.133.362 PACS numbers: 73.63.-b, 73.21.La, 31.15.V-, 74.50.+r