Workshop on QUANTUM INFORMATION AND FOUNDATIONS OF QUANTUM MECHANICS
Quantum Information Processing and Quantum Communications
On unambiguous state discrimination
|aula dottorato - Mercoledì 22 aprile ore 14.00|
|DAGMAR BRUSS, Universitaet Duesseldorf|
Dagmar Bruss completed her PhD in Heidelberg in elementary particle physics.
Spending two postdoc years in Oxford, she moved into the field of quantum
|Distinguishing two non-orthogonal states in an optimal way is a fundamental problem in quantum information theory. If one is not allowed to make an error, this task is called unambiguous state discrimination (USD). A USD measurement is optimal when it minimises the probability of an inconclusive outcome. The optimal solution of USD for two mixed states is not (yet?) analytically known. We show that the optimal measurement is unique, and present a general strategy to find the optimal solution. For the lowest-dimensional non-trivial case (i.e. d = 4) our approach allows to determine the optimal solution in a constructive way, and to understand the properties of its different regimes.|