Resonant single-shot CNOT in remote double quantum dot spin qubits

TL;DR

This paper proposes a framework for implementing a fast, high-fidelity CNOT gate between remote spin qubits in double quantum dots mediated by a superconducting resonator, advancing scalable quantum computing.

Contribution

It introduces a novel ac-driven quantum gate scheme for non-local spin qubits coupled via a resonator, with predicted gate times around 150 ns and fidelities exceeding 90%.

Findings

Gate time near 150 ns predicted.

Fidelity above 90% expected with current tech.

Framework applicable to scalable quantum processors.

Abstract

A critical element towards the realization of scalable quantum processors is non-local coupling between nodes. Scaling connectivity beyond nearest-neighbor interactions requires the implementation of a mediating interaction often termed a 'quantum bus'. Cavity photons have long been used as a bus by the superconducting qubit community, but it has only recently been demonstrated that spin-based qubits in double quantum dot architectures can reach the strong coupling regime and exhibit spin-spin interactions via the exchange of real or virtual photons. Two-qubit gate operations are predicted in the dispersive regime where cavity loss plays a less prominent role. In this work we propose a framework for ac-driven quantum gates, in the context of a CNOT operation, between two non-local single-spin qubits dispersively coupled to a common mode of a superconducting resonator. We expect gate times near 150 ns and fidelities above 90% with existing technology.