Device-Independent Randomness Generation in the Presence of Weak Cross-Talk

TL;DR

This paper proposes that allowing minimal cross-talk between devices in device-independent quantum protocols can enable higher data rates and practical implementation without significantly compromising security.

Contribution

It introduces a relaxed model for device-independent protocols that tolerates weak cross-talk, expanding practical applicability with existing quantum systems.

Findings

Relaxed the perfect isolation assumption in device-independent protocols.

Showed that small cross-talk does not significantly reduce security.

Enabled use of high-data-rate quantum systems like Josephson qubits.

Abstract

Device-independent protocols use nonlocality to certify that they are performing properly. This is achieved via Bell experiments on entangled quantum systems, which are kept isolated from one another during the measurements. However, with present-day technology, perfect isolation comes at the price of experimental complexity and extremely low data rates. Here we argue that for device-independent randomness generation -- and other device-independent protocols where the devices are in the same lab -- we can slightly relax the requirement of perfect isolation, and still retain most of the advantages of the device-independent approach, by allowing a little cross-talk between the devices. This opens up the possibility of using existent experimental systems with high data rates, such as Josephson phase qubits on the same chip, thereby bringing device-independent randomness generation much closer to practical application.