题 目： Compasslike states for sub-Planck sensing

报 告 人： Dr. Naeem Akhtar          浙江师范大学

时   间： 2023年5月23日（星期二）下午2:00

链 接： 腾讯会议：639-282-984

邀 请 人： 汪涛

报告摘要：Heisenberg's principle states that the product of position and momentum uncertainty should be no less than the limit set by Planck's constant (ℏ). This is commonly interpreted to mean that phase-space structures associated with sub-Planck scales do not exist, or do not matter.  However, non-local quantum superpositions (or ‘Schrödinger's cat’ states) that are confined to a phase-space volume characterized by the classical action A, much larger than ℏ, develop spotty structure on the sub-Planck scale, a = ℏ2/A<<1. These sub-Planck-scale phase-space features are found crucial in determining the sensitivity of these states to phase-space displacements. We introduced another set of compasslike (superposition of four coherent states) states having same sub-Planck-scale structures in phase space, and their impact on sensitivity to displacements (perturbations) is investigated. To construct the compass states, we concentrated on the Heisenberg-Weyl, SU(2), and SU(1,1) symmetries. Our work involves a Wigner analysis of such states as well as their susceptibility to phase-space displacements. These states have a substantially higher sensitivity to displacements than the conventional quantum limit, making them useful for quantum sensing applications.

报告人介绍：I have received my PhD degree from the University of Science and Technology of China (USTC) (Major: Physics, Quantum Information Physics) in 2021 under the supervision of Barry C. Sanders. During my PhD, I spent the most of my time at the Wilczeck Quantum Centre at Shanghai Jiao-Tong University, where I worked with Carlos Navarrete-Benlloch. I am currently a postdoctoral fellow at Zhejiang Normal University in group of Prof. Gao Xianlong.