Hybrid atom-photon entangling gates via Gaussian soft control

TL;DR

This paper proposes a theoretical scheme for a hybrid atom-photon controlled-Z gate using Gaussian soft control, enhancing robustness and performance for quantum communication interfaces.

Contribution

It introduces a Gaussian soft control technique to implement a resilient hybrid atom-photon gate in superconducting resonators, improving robustness against parameter variations.

Findings

Gate performance is resilient to atom-photon coupling variations.

Gaussian modulation improves gate fidelity and robustness.

The scheme is less sensitive to stray electric field effects.

Abstract

Hybrid atom-photon gates play an important role for the realization of a quantum interface capable of mapping atomic states to photons for communication across quantum networks. Here, we propose a feasible theoretical scheme for implementing a hybrid atom-photon controlled-Z gate between an atom and a microwave photon in a superconducting coplanar waveguide resonator based on the Gaussian soft control technique. The gate protocol employs a classical auxiliary field that induces an atomic transition between one state of the atomic qubit and Rydberg states for obtaining strong coupling of the atom and microwave resonator. By tailoring the amplitude of this field with Gaussian temporal modulation, the gate performances are improved in various aspects. Numerical simulations demonstrate that the controlled-Z gate based on Gaussian soft control is resilient to the variation of the atom-photon coupling strength, deviation in the gate time, and less sensitive to the Rydberg level shifts caused by stray electric fields.