Preparation and readout of Majorana qubits in magnet-superconductor hybrid systems

TL;DR

This paper proposes a protocol for initializing Majorana-based topological qubits in magnet-superconductor hybrid systems by coupling magnetic chains to a molecule magnet, enabling control over qubit parity and readout.

Contribution

It introduces a novel initialization protocol for Majorana qubits using magnetic molecule coupling, including an augmented qubit definition for easier initialization.

Findings

Successful control of Majorana qubit parity via molecule spin state

Demonstration of initialization of Majorana qubits with different parities

Introduction of an augmented Majorana qubit for simplified readout

Abstract

Initializing the ground state of a quantum bit (qubit) based on Majorana zero modes is one of the most pressing issues for future topological quantum computers. We explore a protocol for initializing such topological qubits based on magnet-superconductor hybrid networks by coupling magnetic chains to a single molecule magnet. The parity of the Majorana state is converted to the presence or absence of a Yu-Shiba-Rusinov state at the molecule. The coupling can be activated by switching the spin state of the molecule, allowing the ground-state parity of the chain to be controlled. We demonstrate that initialization with either parity for a Majorana qubit can be achieved. We then introduce the augmented Majorana qubit, which includes the state of the molecule in the definition of the logical qubit. Using this definition we can initialize a qubit without high-precision timing.