# Rydberg mediated entanglement in a two-dimensional neutral atom qubit array

## TL;DR

This paper demonstrates high-fidelity Rydberg-mediated entanglement in a 2D neutral atom array with 121 sites, achieving Bell state fidelities around 0.88-0.89, and identifies key error sources.

## Contribution

It reports the first high-fidelity two-qubit Rydberg blockade and entanglement in a large 2D atom array with improved experimental techniques.

## Key findings

- Bell state fidelity of 0.86 observed
- Fidelity of 0.88 after SPAM correction
- Gate fidelity of 0.89 with Rydberg $C_Z$ gate

## Abstract

We demonstrate high fidelity two-qubit Rydberg blockade and entanglement in a two-dimensional qubit array. The qubit array is defined by a grid of blue detuned lines of light with 121 sites for trapping atomic qubits. Improved experimental methods have increased the observed Bell state fidelity to $F_{\rm Bell}=0.86(2)$. Accounting for errors in state preparation and measurement (SPAM) we infer a fidelity of $F_{\rm Bell}^{\rm -SPAM}=0.88$. Accounting for errors in single qubit operations we infer that a Bell state created with the Rydberg mediated $C_Z$ gate has a fidelity of $F_{\rm Bell}^{C_Z}=0.89$. Comparison with a detailed error model based on quantum process matrices indicates that finite atom temperature and laser noise are the dominant error sources contributing to the observed gate infidelity.