Coupled quantum electrodynamics in photonic crystal nanocavities

TL;DR

This paper demonstrates that coupled photonic crystal nanocavities with embedded quantum dots can perform universal quantum gates, showing high fidelity and low photon loss even under non-ideal conditions, advancing scalable quantum computing technologies.

Contribution

It introduces a scalable nanocavity array system capable of implementing universal quantum gates with high fidelity using quantum dots.

Findings

Observation of optical analogue of electromagnetically-induced transparency

High-fidelity two-qubit gate operations in the bad cavity limit

Control of spectral lineshapes via single two-level systems

Abstract

We show that a scalable photonic crystal nanocavity array, in which single embedded quantum dots are coherently interacting, can perform as an universal single-operation quantum gate. In a passive system, the optical analogue of electromagnetically-induced-transparency is observed. The presence of a single two-level system in the array dramatically controls the spectral lineshapes. When each cavity couples with a two-level system, our scheme achieves two-qubit gate operations with high fidelity and low photon loss, even in the bad cavity limit and with non-ideal detuning and decoherence.