Demonstration of Microwave Single-shot Quantum Key Distribution

Overview

Journal Nat Commun

Specialty Biology

Date 2024 Aug 30

PMID 39214975

Authors

Florian Fesquet

Fabian Kronowetter

Michael Renger

Wun Kwan Yam

Simon Gandorfer

Kunihiro Inomata

Yasunobu Nakamura

Achim Marx

Rudolf Gross

Kirill G Fedorov

Affiliations

Soon will be listed here.

Abstract

Security of modern classical data encryption often relies on computationally hard problems, which can be trivialized with the advent of quantum computers. A potential remedy for this is quantum communication which takes advantage of the laws of quantum physics to provide secure exchange of information. Here, quantum key distribution (QKD) represents a powerful tool, allowing for unconditionally secure quantum communication between remote parties. At the same time, microwave quantum communication is set to play an important role in future quantum networks because of its natural frequency compatibility with superconducting quantum processors and modern near-distance communication standards. To this end, we present an experimental realization of a continuous-variable QKD protocol based on propagating displaced squeezed microwave states. We use superconducting parametric devices for generation and single-shot quadrature detection of these states. We demonstrate unconditional security in our experimental microwave QKD setting. The security performance is shown to be improved by adding finite trusted noise on the preparation side. Our results indicate feasibility of secure microwave quantum communication with the currently available technology in both open-air (up to ~ 80 m) and cryogenic (over 1000 m) conditions.

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