Reference frame independent quantum key distribution server with telecom tether for on-chip client

TL;DR

This paper presents a reference frame independent quantum key distribution system enabling secure communication between a server and a handheld client over telecom fiber, overcoming fiber birefringence issues with potential for widespread mobile device security.

Contribution

It introduces a practical QKD scheme with an on-chip polarisation rotator for mobile devices, utilizing reference frame independence to handle fiber birefringence, unlike standard protocols.

Findings

Successful demonstration of reference frame independent QKD over telecom fiber.

Overcomes birefringence issues that impair standard QKD protocols.

Enables secure quantum communication with handheld devices via fiber tethering.

Abstract

We demonstrate a client-server quantum key distribution (QKD) scheme, with large resources such as laser and detectors situated at the server-side, which is accessible via telecom-fibre, to a client requiring only an on-chip polarisation rotator, that may be integrated into a handheld device. The detrimental effects of unstable fibre birefringence are overcome by employing the reference frame independent QKD protocol for polarisation qubits in polarisation maintaining fibre, where standard QKD protocols fail, as we show for comparison. This opens the way for quantum enhanced secure communications between companies and members of the general public equipped with handheld mobile devices, via telecom-fibre tethering.