Efficient benchmarking of quantum optical devices via entanglement measures

Killoran, Lutkenhaus

Nathan Killoran, Norbert Lütkenhaus

The quantum nature of an optical device can be verified using benchmarks based on entanglement verification. Without requiring additional resources, we show how to rigourously extend such benchmarks to quantify how well devices preserve entanglement.

F. J. Duarte

Nathan Killoran, Norbert Lütkenhaus

Benchmarks based on entanglement verification can show when optical devices are in the quantum domain. Using no additional resources, we extend existing benchmarks to rigorously quantify the entanglement, covering nearly all of the quantum domain.

Anton Zeilinger, Herbert Joseph Bernstein, Daniel M. Greenberger +2 more

Nathan Killoran, Norbert Lütkenhaus

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 that 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 nonquantitative benchmarks.