Aharonov-Bohm oscillations in the Majorana fermion modulated charge and heat transports through a double-quantum-dot interferometer

Abstract

The Aharonov-Bohm (AB) oscillation effects of electric and heat currents through a parallel double-quantum-dot (DQD) interferometer coupled with Majorana bound states (MBSs) have been investigated. Local and nonlocal Andreev reflections make efficient contributions to the transports, and the AB oscillation structures are modified by the coupled MBSs explicitly. Four linear electric and thermal conductance components are generated by electric potential and temperature differences. The Onsager relation is invalid due to the presence of Andreev reflections in linear response region. However, when the coupling of MBSs is removed, the Andreev reflections disappear, and the Onsager relation is recovered. The magnitudes of electric and thermal conductances are enhanced due to coupling MBSs, and the overall oscillation period changes from flux quantum Φ0 to 2Φ0. We obtain quite different oscillation structures of Seebeck coefficient for the equal-level and unequal-level DQD systems, where peak-valley and higher-lower double-peak structures appear. Meanwhile, the magnitude of Seebeck coefficient is enlarged obviously due to applying MBSs. The AB oscillation behaviors of these coefficients provide novel signatures for detecting Majorana fermions by employing DQD interferometer.