Demonstration of a Quantum Gate using Electromagnetically Induced Transparency

TL;DR

This paper demonstrates a native CNOT quantum gate between neutral atoms using electromagnetically induced transparency and Rydberg interactions, achieving high fidelity and paving the way for scalable quantum computing.

Contribution

It introduces a new EIT-based protocol for implementing multi-qubit CNOT gates with a fixed pulse sequence, simplifying scalable quantum computation.

Findings

Achieved a corrected gate fidelity of 0.82(6).

Prepared a Bell state with a corrected fidelity of 0.66(5).

Outlined technical improvements for fault-tolerant quantum scaling.

Abstract

We demonstrate a native $\mathrm{CNOT}$ gate between two individually addressed neutral atoms based on electromagnetically induced transparency (EIT). This protocol utilizes the strong long-range interactions of Rydberg states to enable conditional state transfer on the target qubit when operated in the blockade regime. An advantage of this scheme is it enables implementation of multi-qubit CNOT$^k$ gates using a pulse sequence independent of qubit number, providing a simple gate for efficient implementation of digital quantum algorithms and stabiliser measurements for quantum error correction. We achieve a loss corrected gate fidelity of $\mathcal{F}_\mathrm{CNOT}^\mathrm{cor} = 0.82(6)$, and prepare an entangled Bell state with $\mathcal{F}_\mathrm{Bell}^\mathrm{cor} = 0.66(5)$, limited at present by laser power. We present a number of technical improvements to advance this to a level required for fault-tolerant scaling.