Generation of optical Gottesman-Kitaev-Preskill states with cavity QED

TL;DR

This paper proposes a cavity QED-based method to generate optical GKP states, demonstrating potential for scalable, deterministic, and high-quality quantum states suitable for fault-tolerant quantum computing.

Contribution

It introduces a novel cavity QED protocol for GKP state generation, combining it with breeding techniques to relax system quality requirements and enable near-future experimental realization.

Findings

GKP states with over 10 dB squeezing are achievable in upcoming experiments.

The method is fully deterministic, improving scalability over probabilistic approaches.

Simulation shows robustness in realistic noisy cavity QED systems.

Abstract

Gottesman-Kitaev-Preskill (GKP) states are a central resource for fault-tolerant optical continuous-variable quantum computing and communication. However, their realization in the optical domain remains to be demonstrated. Here we propose a method for preparing GKP states using a cavity QED system as the only non-Gaussian element. This system can be realized in several platforms such as trapped atoms, quantum dots or diamond color centers. We simulate the protocol with finite-cooperativity systems to evaluate the achievable quality of the produced GKP states in realistic noisy systems. We further combine the protocol with the previously proposed breeding protocol by Vasconcelos et al. to relax the demands on the quality of the QED system. We find that GKP states with more than 10 dB squeezing could be achieved in near-future experiments. Additionally, the approach can be made fully deterministic, thus providing a more scalable and hardware-efficient approach compared to probabilistic approaches based on photon counting.