Entangling distant resonant exchange qubits via circuit quantum electrodynamics

TL;DR

This paper explores methods to entangle distant resonant exchange qubits in silicon using circuit quantum electrodynamics, analyzing gate fidelities and relaxation rates to demonstrate strong coupling potential.

Contribution

It introduces three approaches for resonator-mediated two-qubit gates in resonant exchange qubits, combining spin coherence with circuit QED for long-range entanglement.

Findings

High entangling gate fidelities achievable

Strong coupling regime is feasible in silicon triple dots

Resonator-mediated gates are robust and rapid

Abstract

We investigate a hybrid quantum system consisting of spatially separated resonant exchange qubits, defined in three-electron semiconductor triple quantum dots, that are coupled via a superconducting transmission line resonator. Drawing on methods from circuit quantum electrodynamics and Hartmann-Hahn double resonance techniques, we analyze three specific approaches for implementing resonator-mediated two-qubit entangling gates in both dispersive and resonant regimes of interaction. We calculate entangling gate fidelities as well as the rate of relaxation via phonons for resonant exchange qubits in silicon triple dots and show that such an implementation is particularly well-suited to achieving the strong coupling regime. Our approach combines the favorable coherence properties of encoded spin qubits in silicon with the rapid and robust long-range entanglement provided by circuit QED systems.