Analysis of quantum interface between Rydberg-blocked atomic ensemble and cavity optical field with two-photon transition

TL;DR

This paper explores a quantum interface using Rydberg-blocked atomic ensembles in a cavity, demonstrating a controlled-PHASE gate for quantum information processing with manageable experimental requirements.

Contribution

It introduces a theoretical analysis of a Rydberg-based atom-photon interface implementing a Jaynes-Cummings model and a robust quantum gate with realistic experimental conditions.

Findings

Demonstrates the feasibility of a controlled-PHASE gate between photonic and matter qubits.

Shows the system's robustness against major decoherence factors.

Provides guidelines for experimental implementation with alkali atoms.

Abstract

We study the atom-photon quantum interface with intracavity Rydberg-blocked atomic ensemble where the ground-Rydberg transition is realized by two-photon transition. Via theoretical analysis, we report our recent findings of the Jaynes-Cummings model on optical domain and robust atom-photon quantum gate enabled by this platform. The requirement on the implementation is mild which includes an optical cavity of moderately high finesse, typical alkali atoms such as Rb or Cs and the condition that cold atomic ensemble is well within the Rydberg blockade radius. The analysis focuses on the atomic ensemble's collective coupling to the quantized optical field in the cavity mode. We demonstrate its capability to serve as a controlled-PHASE gate between photonic qubits and matter qubits. The detrimental effects associated with several major decoherence factors of this system are also considered in the analysis.