Strong quantitative benchmarking of quantum optical devices

TL;DR

This paper introduces a new method to quantitatively assess the degree of quantumness in optical devices, extending existing benchmarks without requiring extra information, thus enabling better verification of quantum advantages.

Contribution

It presents a novel approach based on entanglement measures and state truncation to quantify how strongly optical devices operate within the quantum domain.

Findings

Provides a quantitative extension to existing quantum benchmarks.

Requires no additional information beyond current benchmarks.

Enables precise characterization of device quantumness.

Abstract

Quantum communication devices, such as quantum repeaters, quantum memories, or quantum channels, are unavoidably exposed to imperfections. However, the presence of imperfections can be tolerated, as long as we can verify such devices retain their quantum advantages. Benchmarks based on witnessing entanglement have proven useful for verifying the true quantum nature of these devices. The next challenge is to characterize how strongly a device is within the quantum domain. We present a method, based on entanglement measures and rigorous state truncation, which allows us to characterize the degree of quantumness of optical devices. This method serves as a quantitative extension to a large class of previously-known quantum benchmarks, requiring no additional information beyond what is already used for the non-quantitative benchmarks.