Multiphoton resonances for all-optical quantum logic with multiple cavities

TL;DR

This paper presents a theoretical framework for multi-photon resonances in multi-mode cavities, enabling quantum gate operations with high fidelity for scalable quantum computing.

Contribution

It introduces a novel theory for cavity-enhanced multi-photon resonances and demonstrates how to implement universal quantum gates using multi-mode cavities and atomic interactions.

Findings

Predicted resonance locations using effective Hamiltonians

Proposed high-fidelity quantum gate implementations

System shows potential for scalable quantum computing

Abstract

We develop a theory for the interaction of multi-level atoms with multi-mode cavities yielding cavity-enhanced multi-photon resonances. The locations of the resonances are predicted from the use of effective two- and three-level Hamiltonians. As an application we show that quantum gates can be realised when photonic qubits are encoded on the cavity modes in arrangements where ancilla atoms transit the cavity. The fidelity of operations is increased by conditional measurements on the atom and by the use of a selected, dual-rail, Hilbert space. A universal set of gates is proposed, including the Fredkin gate and iSWAP operation; the system seems promising for scalability.