Fast atom-photon entangling gates with a superconducting coplanar waveguide

TL;DR

This paper proposes a fast, one-step controlled-Z gate between a neutral atom and a microwave photon in a superconducting coplanar waveguide, enabling efficient hybrid quantum interfaces with minimal control complexity.

Contribution

It introduces a simplified, one-pulse controlled-Z gate protocol for atom-photon entanglement in superconducting circuits, extending previous methods.

Findings

The gate operates with a single laser pulse.

It achieves entanglement between atoms and microwave photons.

The protocol is efficient and experimentally feasible.

Abstract

Entanglement between atoms and microwave photons in a superconducting coplanar waveguide~(SCW) can enable hybrid quantum devices and interface static and flying qubits. We study a one-step controlled-Z~(C$_{\text{Z}}$) gate between a neutral atom trapped near a SCW and a microwave mode in the SCW, which is an extension of the gate proposed in [J. D. Pritchard, et.al., Phys. Rev. A 89, 010301(R) (2014)]. The gate protocol is simple and requires one laser pulse for exciting a transition between the ground and Rydberg states of the neutral atom.