Cavity-assisted controlled phase-flip gates

TL;DR

This paper proposes three cavity-mediated controlled phase-flip gate schemes suitable for quantum networks, emphasizing high cooperativity operation without requiring strong coupling, and analyzes their fidelities considering realistic imperfections.

Contribution

It introduces three novel cavity-assisted controlled phase-flip gate schemes that operate efficiently with high cooperativity, expanding practical options for quantum network implementations.

Findings

All schemes can operate with high fidelity in high cooperativity regimes.

Fidelity depends on realistic imperfections, with optimal conditions identified for each scheme.

Comparison guides system design choices for quantum network applications.

Abstract

Cavity-mediated two-qubit gates, for example between solid-state spins, are attractive for quantum network applications. We propose three schemes to implement a controlled phase-flip gate mediated by a cavity. The main advantage of all these schemes is the possibility to perform them using a cavity with high cooperativity, but not in the strong coupling regime. We calculate the fidelity of each scheme in detail, taking into account the most important realistic imperfections, and compare them to highlight the optimal conditions for each scheme. Using these results, we discuss which quantum system characteristics might favor one scheme over another.