Spin Superfluid Josephson Phase Qubits

TL;DR

This paper proposes a new type of magnetic qubit based on spin superfluidity and spin Hall effects, offering scalable quantum computing with potentially higher operational temperatures than superconducting qubits.

Contribution

Introduction of a macroscopic spintronic qubit utilizing spin superfluidity, with full electrical control and readout, and the concept of a magnetic quantum annealer.

Findings

Proposed a scalable solid-state magnetic qubit based on spin superfluidity.

Showed that the operational temperature could surpass superconducting qubits.

Outlined the potential for a magnetic quantum annealer.

Abstract

A macroscopic spintronic qubit based on spin superfluidity and spin Hall phenomena is proposed. This magnetic quantum information processing device realizes the spin-supercurrent analog of the superconducting phase qubit and allows for full electrical control and readout. We also show that an array of interacting magnetic phase qubits can realize a quantum annealer. These devices can be built through standard solid-state fabrication technology, allowing for scalability. However, the upper bound for the operational temperature can, in principle, be higher than the superconducting counterpart, as it is ultimately governed by the magnetic ordering temperatures, which could be much higher than the critical temperatures of the conventional superconducting devices.