SWAP gate between a Majorana qubit and a parity-protected superconducting qubit

TL;DR

This paper proposes a hybrid quantum architecture coupling a Majorana qubit with a parity-protected superconducting qubit, enabling a SWAP gate for efficient quantum information transfer between topological and conventional qubits.

Contribution

It introduces a novel hybrid system integrating Majorana and superconducting qubits with a SWAP gate for improved quantum memory and processing.

Findings

Demonstrates implementation of a SWAP gate between Majorana and superconducting qubits.

Shows the potential for combining fast gates with topologically protected quantum memory.

Proposes a practical architecture using gate-tunable semiconducting wires with Majorana modes.

Abstract

High fidelity quantum information processing requires a combination of fast gates and long-lived quantum memories. In this work, we propose a hybrid architecture, where a parity-protected superconducting qubit is directly coupled to a Majorana qubit, which plays the role of a quantum memory. The superconducting qubit is based upon a $\pi$-periodic Josephson junction realized with gate-tunable semiconducting wires, where the tunneling of individual Cooper pairs is suppressed. One of the wires additionally contains four Majorana zero modes that define a qubit. We demonstrate that this enables the implementation of a SWAP gate, allowing for the transduction of quantum information between the topological and conventional qubit. This architecture combines fast gates, which can be realized with the superconducting qubit, with a topologically protected Majorana memory.