Programmable unambiguous discriminator between two arbitrarily distributed unknown latitudinal states

Abstract:

Quantum state discrimination is a very important problem in the field of quantum information and quantum computation. Usually，the equatorial state, a special latitudinal state, is often used to study quantum communication both from theoretical and experimental perspectives. In this paper, we mainly use Neumark's theorem and the optical realization of the programmable quantum state discriminator to investigate how to unambiguously discriminate two unknown latitudinal states of arbitrary distribution. The detection operators and the successful probability are derived. Furthermore, we find that the detection operators obtained in this paper are the same as the optimal detection operators obtained from the unambiguous discrimination of two unknown latitudinal states of uniform distribution. These results have important reference significance for the construction of the programmable quantum discriminator in laboratory.