报告时间：8月10日下午4点

报告地点：近代物理系210会议室

报告人： 香港大学 Yuxiang Yang博士

报告题目： Compression for identically prepared quantum states

报告摘要：Quantum states prepared in the identical form are the typical resources considered in quantum metrology. In this talk, I will discuss the compression of n quantum systems, each prepared in the same state belonging to a given parametric family of quantum states. For a family of states with f independent parameters, we devise an asymptotically faithful protocol that requires a hybrid memory of size (f /2) log n, including both quantum and classical bits. The protocol is optimal in the sense that it minimizes the overall cost of quantum and classical bits. The application of the compression protocol includes a quantum stopwatch mechanism, which achieves the ultimate precision in time metrology fixing the amount of accessible memory.

References:

1. Y. Yang, G. Bai, G. Chiribella and M. Hayashi, IEEE Trans. Info. Theory, 64, 4766-4783 (2018).

2. Y. Yang, G. Chiribella, M. Hayashi, Proc. R. Soc. A, 474.20170773 (2018).

3. Y. Yang, G. Chiribella, M. Hayashi, Phys. Rev. Lett.,117.090502 (2016).

报告人简介：Yuxiang Yang received a Ph. D. degree in Computer Science from The University of Hong Kong in 2018 and a B. S. degree in Physics from Tsinghua University in 2013. In 2017, he was awarded the Microsoft Research Asia Fellowship. His research interests include quantum information theory and quantum computation.