A counterfactual Rydberg gate for photons

TL;DR

This paper proposes a novel two-photon entangling gate for quantum computing that utilizes a Rydberg atom and a counterfactual protocol to achieve efficient photon interactions.

Contribution

It introduces a new counterfactual Rydberg gate design that leverages atomic dipole blockade to control photon absorption, enabling efficient quantum gates.

Findings

The gate operates with high fidelity due to the counterfactual protocol.

The system effectively uses a single Rydberg atom to mediate photon entanglement.

Potential for scalable quantum photonic computation.

Abstract

Quantum computation with photons requires efficient two photon gates. We put forward a two photon entangling gate which uses an intermediate atomic system. The system includes a single Rydberg atom which can switch on and off photon absorption in an ensemble using the dipole blockade. The gate is based in a counterfactual protocol. The mere possibility of an absorption that can only occur with a vanishing probability steers the photons to the desired final state.