Revisiting unambiguous discrimination

The unambiguous discrimination is a standard strategy of detecting linearly independent quantum states and has many applications in quantum information processing. In the standard unambiguous discrimination, the measuring operators contain two types of measuring operators: the success operators and an inconclusive operator. It is conventionally regarded that an inconclusive operator gives no more information about the input states. In this paper, we propose a new unambiguous discrimination by replacing the inconclusive operator by the correct operators, and thus, more information about input states can be obtained. We take three examples to demonstrate the efficiency of our detection scheme. Our scenario improves the standard unambiguous discrimination.