Proposal for Implementing Device-Independent Quantum Key Distribution based on a Heralded Qubit Amplification

TL;DR

This paper proposes a heralded qubit amplifier using linear optics and single-photon sources to address channel loss issues in device-independent quantum key distribution, aiming to enable secure optical Bell tests.

Contribution

It introduces a novel heralded qubit amplifier design that mitigates channel loss effects, facilitating practical implementation of DIQKD.

Findings

Proposes a heralded qubit amplifier for DIQKD

Addresses detection loophole caused by photon losses

Provides a pathway for secure optical Bell tests

Abstract

In device-independent quantum key distribution (DIQKD), the violation of a Bell inequality is exploited to establish a shared key that is secure independently of the internal workings of the QKD devices. An experimental implementation of DIQKD, however, is still awaited, since hitherto all optical Bell tests are subject to the detection loophole, making the protocol unsecured. In particular, photon losses in the quantum channel represent a fundamental limitation for DIQKD. Here, we introduce a heralded qubit amplifier based on single-photon sources and linear optics that provides a realistic solution to overcome the problem of channel losses in Bell tests.