Viewing Majorana Bound States by Rabi Oscillations

TL;DR

This paper proposes a method to detect Majorana bound states using Rabi oscillations in a quantum dot-SQUID setup, revealing unique properties like fractional Josephson relations through electron occupation measurements.

Contribution

It introduces a novel experimental scheme combining a quantum dot and SQUID to observe Rabi oscillations involving Majorana bound states, enabling their detection and characterization.

Findings

Rabi oscillations can be induced among states involving MBSs.

The fractional Josephson relation $ ext{cos}(rac{ ext{pi} ext{Phi}}{ ext{Phi}_0})$ can be observed.

Analytic Floquet theory and numerical simulations agree well.

Abstract

Rabi oscillation is a pure quantum phenomenon where the system jumps forth and back between two quantum levels under stimulation of a microwave, and a resonance occurs when the energy difference is matched by the photon energy. Rabi oscillations have been observed in various quantum systems so far, and especially are used to demonstrate the quantum coherence of quantum bits. In the present work, we explore Rabi oscillation in a system accommodating the elusive Majorana bound states (MBSs) under intensive search recently. The proposed setup is constructed by a quantum dot (QD) and a superconducting quantum interference device (SQUID), where a semiconductor nanowire with spin-orbital coupling in the topological state is introduced to form Josephson junction. When the coupling between QD and the Josephson junction is tuned by an ac gate voltage, Rabi oscillation takes place among quantum states formed by QD and MBSs, which makes it possible to reveal bizarre properties of MBSs by sensing the electron occupation on QD. Especially, one should be able to observe the fractional Josephson relation $\cos(\pi\Phi/\Phi_0)$ unique to MBSs with $\Phi$ the magnetic flux applied in the SQUID and $\Phi_0=hc/2e$ the flux quantum. The system has been investigated in terms of the analytic Floquet theorem and numerical simulations with fine agreement.