|| Asymptotic Separation Between Adaptive and Non-adaptive Strategies in Quantum Channel Discrimination
||Farzin Salek, Technical University of Munich, Germany; Masahito Hayashi, Southern University of Science and Technology, China; Andreas Winter, Universitat Autònoma de Barcelona, Spain|
||D3-S3-T4: Quantum Detection & Estimation
||Wednesday, 14 July, 22:40 - 23:00
||Wednesday, 14 July, 23:00 - 23:20
We present a broad investigation of asymptotic binary hypothesis testing, when each hypothesis represents asymptotically many independent instances of a quantum channel, and the tests are based on using the unknown channel multiple times and observing its output at the end. Unlike the familiar setting of quantum states as hypotheses, there is a fundamental distinction between adaptive and non-adaptive strategies with respect to the channel uses, and we introduce a number of further variants of the discrimination tasks by imposing different restrictions on the test strategies. Our main result is the first separation between adaptive and non-adaptive symmetric hypothesis testing exponents for quantum channels, which we derive from a general lower bound on the error probability for non-adaptive strategies; the concrete example we analyze is a pair of entanglementbreaking channels. Full details in .