Speaker: 郭志华教授

Title: Freezing Imaginarity Measures with Real Quantum Operations

Language: Chinese

Time & Venue: 2024.07.19 17:00-18:00 数学院南楼N620

Abstract: Imaginarity plays an essential role in the quantum information processing task. Usually, real operations do not increase imaginarity measures. We aim to discuss freezing of imaginarity measures with real operations. It is proved that a real operation freezes all imaginarity measures of a state if and only if it freezes the relative entropy measure of imaginarity of the state if and only if the error generated by the real operation at the state can be corrected by a real operation. In the qubit case, real operations that freeze imaginarity measures based on trace distance and relative entropy are characterized, respectively. The freezing of imaginarity measure based on trace distance is not necessarily dilated into multipartite systems, while that based on the Tsallis relative entropy can be dilated into multipartite systems. Finally, we characterize real local operations that freeze the imaginarity measure based on trace distance of a special type of X-states in a multi-qubit system.