热原子系统中非耗散反PT对称奇异点的观测  

Observation of Exceptional Point in Non-Dissipative Anti-Parity-Time-Symmetry with Hot Atoms

作　　者：黄铖楠 钮月萍[1] 龚尚庆[1] 张示城 HUANG Chengnan;NIU Yueping;GONG Shangqing;ZHANG Shicheng(School of Physics,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学物理学院,上海200237

出　　处：《华东理工大学学报(自然科学版)》2025年第2期285-290,共6页Journal of East China University of Science and Technology

基　　金：国家自然科学基金(12043007);上海市优秀学科带头人计划(21XD1400700);上海市教委科技创新重点项目(2023ZKZD39)。

摘　　要：非厄米系统在奇异点(Exceptional points, EPs)附近对非厄米参量有着极高的灵敏度,这使得基于EP的精密传感在诸多领域得到应用。然而,传统的宇称时间反演(Parity-time,PT)对称系统需要引入增益和损耗,这会引起量子噪声问题。反PT对称系统可以在不引入线性增益和损耗的同时保持高灵敏度,但是热原子非耗散反PT对称系统中EP的实验观测仍是一个难点。本文通过热原子系统的远失谐四波混频效应证明了非耗散反PT对称性,并通过实验观察到EP,有望为室温条件下的量子传感和量子信息处理等应用提供一种可行的方案。Parity-time(PT)symmetric systems are extremely sensitive to non-Hermitian parametric perturbations near the exceptional point(EP),which has led to the widespread use of EP-based precision sensing in a wide variety of systems.However,conventional PT symmetric systems require the introduction of gains and losses,which can cause quantum noise problems.The anti-PT-symmetric system can be used without introducing gains and losses and also possesses an extremely high sensitivity in the vicinity of the EP.However,the experimental verification of EP in nondissipative anti-PT-symmetric systems with hot atoms has not yet been demonstrated.Here,we demonstrate nondissipative anti-PT-symmetry through far-detuned four wave mixing(FWM)in hot atoms and successfully observe the EP,which will provide a practicable means for applications such as quantum sensing and quantum information processing at ambient conditions.

关 键 词：反PT对称 EP 热原子 四波混频 非厄米 

分 类 号：O437[机械工程—光学工程]