基于镜像电荷法探测液氦表面电子的自旋态  

Detecting electron spin on liquid helium surface by using the image-charge approach

作　　者：王婷[1] 张淼[1] WANG Ting;ZHANG Miao(School of Physics Science and Technology,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学物理科学与技术学院,成都610031

出　　处：《原子与分子物理学报》2023年第6期123-129,共7页Journal of Atomic and Molecular Physics

摘　　要：文献[Phys.Rev.A,2006,74:052338]的理论研究表明液氦上电子自旋具有长达100秒的相干时间,因此在实施量子信息处理方面具有很大的应用前景.然而,这一理论还未得到实验的证实.液氦上电子的自旋-轨道耦合可以为电子自旋探测提供一种可选的方法.理论上,电子自旋-轨道耦合可以由液氦膜下方的微电极电流产生.在微波驱动下,电子发生电偶极跃迁,导致电子距离液氦表面的平均高度发生改变.利用镜像电荷法[Phys.Rev.Lett.,2019,123:086801],电子的这种轨道运动可以被实验测量.建立基于液氦上电子-自旋轨道耦合的密度矩阵方程,并数值求解镜像电荷的振动行为.结果表明不同的自旋态将会引起不同的感应电流,这种差异提供了一种可选的电子自旋探测方法.The theoretical study[Phys.Rev.A,2006,74:052338]shows that electron spin on liquid helium surface has a coherence time of up to 100 seconds,and thus could be used for implementing quantum information processing.However,this theory has not been experimentally verified,yet.The spin-orbit coupling of electrons on liquid helium may provide an alternative method for electron spin detection.Theoretically,the electronic spin-orbit coupling generated by microelectrode currents under the liquid helium membrane,together with the electric dipole transitions driven by microwaves,shall result in a spin-dependent height of electrons above liquid helium surface.This orbital motion is experimentally detectable by using the image-charge method[Phys.Rev.Lett.,2019,123:086801].A density matrix equation with electron spin-orbit coupling is established,and the vibrational motion of the image charge is numerically solved.The results show that different spin states will induce different image-currents.This difference provides an alternative method for electron spin detection.

关 键 词：密度矩阵方程 液氦上电子 自旋-轨道耦合 镜像电荷法 

分 类 号：O431.2[机械工程—光学工程]