Probing the quantumness of channels with mixed states

Hauke Häseler, Norbert Lütkenhaus

Published 2009-07-03, updated 2009-10-09Version 2

We present an alternative approach to the derivation of benchmarks for quantum channels, such as memory or teleportation channels. Using the concept of effective entanglement and the verification thereof, a testing procedure is derived which demands very few experimental resources. The procedure is generalized by allowing for mixed test states. By constructing optimized measure & re-prepare channels, the benchmarks are found to be very tight in the considered experimental regimes.