报告人：江敏 博士后（中国科学技术大学）

时 间：2021年6月11日(周五) 上午10:00-11:00

地 点：中心教学楼501室

摘要：

Ultralight axion-like particles (ALPs) are well-motivated dark matter candidates introduced by theories beyond the standard model. However, the constraints on the existence of ALPs through existing laboratory experiments are hindered by their current sensitivities, which are usually weaker than astrophysical limits. In this talk, I will introduce our recently developed quantum sensors (“spin-based amplifier” and “Floquet maser”) to search for ALPs in the mass range that spans about five decades from 0.01 feV to 744 feV. Our sensor makes use of hyperpolarized long-lived nuclear spins as a pre-amplifier that effectively enhances coherently oscillating axion-like dark-matter field by a factor of >100. Using spin-based amplifiers, we achieve an ultrahigh magnetic sensitivity of 18 fT/Hz1/2, which is significantly better than state-of-the-art nuclear-spin magnetometers. Using Floquet masers, we demonstrated the best magnetic field sensitivity in the ultralow-frequency region. Our experiment constrains the parameter space describing the coupling of ALPs to nucleons over our mass range, improving over previous laboratory limits by at least five orders of magnitude. Our measurements also constrain the ALP-nucleon quadratic interaction and dark photon-nucleon interaction with new limits beyond the astrophysical ones.

简历：

Min Jiang received his B. S. degree and Ph. D. degree in University of Science and Technology of China, China. Now he is a postdoc fellow in the same University. His interests mainly focus on quantum precision measurements and nuclear magnetic resonance, including spin maser, ultra-high sensitivity atomic magnetometer, ultra-low field nuclear magnetic resonance, and tests of fundamental physics. His works are ongoing towards developing sensitive techniques for applied science and search for new physics beyond Standard Model.

联系方式：bozhang_quantum@bit.edu.cn

邀请人：张博 预聘助理教授

网 址：/

承办单位：物理学院、量子技术研究中心