谐振子势阱中双费米原子光钟的碰撞频移  

Collision clock shift of two Fermi atoms in harmonic potentials

作　　者：陈泽锐 刘光存 俞振华 Chen Ze-Rui;Liu Guang-Cun;Yu Zhen-Hua(Guangdong Provincial Key Laboratory of Quantum Metrology and Sensing,School of Physics and Astronomy,Sun Yat-Sen University,Zhuhai 519082,China)

机构地区：[1]中山大学物理与天文学院,广东省量子精密测量与传感重点实验室,珠海519082

出　　处：《物理学报》2021年第18期57-64,共8页Acta Physica Sinica

基　　金：广东省重点领域研发计划(批准号:2019B030330001);国家自然科学基金(批准号:11474179,11722438,91736103,12074440)资助的课题.

摘　　要：原子钟提供了时间的标准,但原子间的相互作用往往限制原子钟的精度.本文理论研究了谐振子势阱中双费米原子光钟由于原子间的短程相互作用而在拉比频谱中引起的碰撞频移.考虑到原子光钟中短程相互作用一般较弱,并且晶格光的参数在Lamb-Dicke区间中,本文近似费米原子的外态不发生改变,进而推导出原子内态在拉比探测光驱动下满足的运动方程.微扰求解运动方程,得到一阶解的解析表达式,从而得到了拉比频谱的碰撞频移依赖于拉比探测光参数与在原子特定外态中相互作用的表达式.最后,利用谐振子势阱中格林函数的解析表达式,得到了有限温下碰撞频移与原子间相互作用的关系.研究结果表明,实验中可以通过精密测量原子光钟的频移获得原子间相互作用的信息.Atomic clocks provide the most accurate definition for time.The precision of atomic clock has been improved by many orders of magnitude since the first atomic clock was built.However,the interatomic interaction usually suppress the precision of atomic clock.As a result,it is especially meaningful to study the interaction effect in atomic clock,which is considered to be helpful in improving the precision and accuracy of atomic clock.In order to characterize the collision effect induced clock shift,we theoretically study the collision clock shift in the Rabi spectrum,caused by the short-range interaction between two Fermi atoms in harmonic potential.Given that the short-range interatomic interaction is generally weak,and that the parameters of external lattice laser field are in the Lamb-Dicke regime,we make an approximation that the spatial wave-function of the Fermi atoms does not change,and then derive the motion equation for the internal wave-function under the external Rabi driving field.We solve the equation of motion by the perturbative method,and obtain the solution to first order,and thus derive the expression of the collision clock shift of the Rabi spectrum in terms of the interatomic interaction and the external Rabi driving laser field parameters for specific spatial wave-functions of atoms.Finally,we use the exact expression of the Green’s function in harmonic potential to obtain the averaged clock shift of collision at finite temperatures.Our results relate the atomic interaction with atomic clock shift,and provide a unified description of all partial waves of atomic interaction induced clock shift.Therefore,it becomes much more convenient to study the contributions of different partial waves to atomic clock shift.On the other hand,our results indicate that through precisely measuring the clock shift,the information about the interatomic interactions can also be obtained.In addition,our results for two interacting atoms can inspire the future study of real many-body interacting system which will be

关 键 词：费米子系统 时钟碰撞频移 原子钟 

分 类 号：TH714.14[机械工程—测试计量技术及仪器]