Chinese Phys. B 30 010301 (2021)

Double-dot interferometer for quantum measurement of Majorana qubits and stabilizers

Kai Zhou¹, Cheng Zhang¹, Lupei Qin² and Xin-Qi Li^2,1

1 Department of Physics, Beijing Normal University, Beijing 100875, China

2 Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, Tianjin 300072, China

Abstract

Motivated by the need of quantum measurement of Majorana qubits and surface-code stabilizers, we analyze the performance of a double-dot interferometer under the influence of environment noise. The double-dot setup design allows accounting for the full multiple tunneling process between the dots through the Majorana island, within a master equation approach. In the co-tunneling regime, which results in a Majorana-mediated effective coupling between the dots, the master equation approach allows us to obtain analytic solutions for the measurement currents. The measurement quality, characterized by figures of merit such as the visibility of measurement signals, is carried out in regard to the unusual decoherence effect rather than 'which-path' dephasing. The results obtained in this work are expected to be useful for future experiments of Majorana qubit and stabilizer measurements.