物理学院学术报告（第23期）

报告题目：Quantum Sensing and Metrology with Optically  Guided Atom Interferometer

报告专家：Mingjie Xin    Nanyang Technological University

报告时间：2025年05月15日（周四）10: 00

报告地点：理6栋302      邀请人：颜辉

报告内容：

Atom interferometry is a versatile technique utilized for the precise measurement of fundamental constants, such as the Newtonian gravitational constant and the fine-structure constant, while also serving as a powerful tool for testing general relativity and exploring new physics. At the same time, atom interferometers are currently moving out of the laboratory, working as highly sensitive quantum sensors for various applications, such as gravimeters, inertial sensing for navigation, and probing geodesy and geophysics. In typical atom interferometers, precision is limited by the time scale of the measurement, which, in turn, is constrained by the distance that the atoms drop. Miniaturization of interferometer setups typically reduces its performance, thereby limiting its applications. To address this, coherent manipulation of guided ultra-cold atoms has been attempted, with the aim of enhancing the performance of atom interferometers and further developing miniaturized quantum devices.

In this talk, I will present our efforts in confining cold atoms in a hollow-core photonic crystal fiber and highlight several key cold-atom experiments investigated in this hollow-core waveguide environment. In the second part of this talk, I will demonstrate the realization of rapid quantum squeezing that overcomes the quantum speed limit using atoms trapped in optical lattice. This achievement holds potential applications for quantum-enhanced sensing and continuous-variable quantum information processing. Finally, I will highlight our recent breakthroughs in direct laser cooling of atoms to Bose-Einstein condensate without the necessity for time-consuming evaporative cooling methods. This enables us to use BEC as a robust and fast source for feeding an interferometer with a bright solitonic matter wave in a horizontal optical waveguide. The results demonstrate the high potential of interferometers operated with quantum gases for probing the fundamental concepts of quantum mechanics and general relativity.

专家简介：

Mingjie Xin is a postdoctoral research fellow at Nanyang Technological University, where he also completed his PhD. His research focuses on quantum sensing and precision measurement using cold atoms, with a particular emphasis on developing atom interferometers trapped in optical waveguides. He is also exploring methods for the rapid creation of quantum degenerate gases and developing atom interferometers that operate with these quantum gases, both for probing fundamental physics and advancing applied inertial sensing technologies.