Speaker: 朱黄俊研究员，复旦大学

Inviter: 李楠副研究员

Title: Information Theoretic Significance of Projective Measurements

Language: Chinese

Time & Venue: 2024.08.30 14:30-15:30 思源楼 723

Abstract: Projective measurements in quantum theory have a very simple algebraic definition, but their information theoretic significance is quite elusive. To shed light on this problem, here we introduce a simple order relation based on the concentration of Fisher information, which complements the familiar data-processing order. Then we show that projective measurements are quantum measurements that can extract Fisher information as concentrated as possible and are Fisher-sharp in a precise sense. Furthermore, we introduce a sharpness index and show that it is determined by the finest projective measurement among the coarse graining of a given measurement. Our work is of intrinsic interest to foundational studies on quantum measurements and quantum estimation theory (arXiv:2305.14110).