Observation of Entanglement Between Itinerant Microwave Photons and a Superconducting Qubit

TL;DR

This paper demonstrates the on-demand creation and detailed characterization of entangled states between a superconducting qubit and propagating microwave photons, advancing quantum communication capabilities.

Contribution

It reports the first high-fidelity entanglement between a superconducting qubit and itinerant microwave photons with comprehensive correlation analysis.

Findings

Successful generation of Bell-type entangled states

High-fidelity entanglement demonstrated

Effective measurement of qubit-photon correlations

Abstract

A localized qubit entangled with a propagating quantum field is well suited to study non-local aspects of quantum mechanics and may also provide a channel to communicate between spatially separated nodes in a quantum network. Here, we report the on demand generation and characterization of Bell-type entangled states between a superconducting qubit and propagating microwave fields composed of zero, one and two-photon Fock states. Using low noise linear amplification and efficient data acquisition we extract all relevant correlations between the qubit and the photon states and demonstrate entanglement with high fidelity.