Confinement of gaseous atoms with superfluid helium film and its application to the test of time-reversal symmetry

超流氦膜对气态原子的约束及其在时间反演对称性检验中的应用

基本信息

批准号：
11304023
负责人：
YABUZAKI Tsutomu
金额：
$ 24.94万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11304023/
关键词：
Gaseous alkali-metal atom Optical pumping Spin-polarization Superfluid helium Permanent electric dipole moment Laser spectroscopy High precision measurement エキシマー

项目摘要

The purpose of this project is to realize the alkali vapor cell at liquid helium temperature, by coating the cell walls with superfluid helium film, suitable for the spin- related fundamental physics, particularly to the measurement of atomic electric dipole moment (EDM) for the test of time reversal symmetry. Through this project we could get various important results as follows.(1) We could realize experimentally alkali vapor cell, where the life of gaseous alkali atoms was as long as 10-100 s.(2) We could develop a novel method of production of alkali gaseous atoms, so called "light-induced atom desorption LIAD" method, witch can produce gaseous atoms with weak cw light, without strong convection.(3) It was found that the superfluidity of the liquid helium on the wall plays an important role for the LIAD, and the mechanism could be revealed.(4) Optical pumping experiment was made to the produced atoms in the cold cell. We found that the spin-relaxation time was determined by the lifetime of atoms 10-100 s.(5) We developed the method of atomic spin with the Faraday effect, which minimized the perturbation to the spin state. We also proposed the method of spin non-demolition measurement, which is very suitable for the atomic EDM measurement.(7) We also proposed and studied a novel method to observe the special distribution of spin polarization, optical magnetic-resonance imaging.(8) As a new effect of cold helium gas to alkali-metal atom, we found the formation of excimer and exciplexes, where helium atoms are sticking to the excited state alkali atoms. Trough spectroscopic studies of these excited-state molecules, we could determine their energies, including vibrational energies, and could get the information of formation.

本项目的目的是通过在池壁上涂覆超流氦薄膜，实现液氦温度下的碱蒸气电池，适用于自旋相关的基础物理，特别是原子电偶极矩（EDM）的测量。时间反转对称性检验。通过这个项目，我们可以得到以下几个重要成果：（1）我们可以在实验上实现碱蒸汽电池，其中气态碱原子的寿命长达10-100秒。（2）我们可以开发一种新的生产方法碱性气态原子，即所谓的“光诱导原子解吸LIAD”方法，可以产生弱连续光的气态原子，无需强对流。（3）发现壁上液氦的超流动性(4)对冷室中产生的原子进行了光泵浦实验。我们发现自旋弛豫时间由原子的寿命10-100秒决定。(5)我们发展了利用法拉第效应的原子自旋方法，最大限度地减少了对自旋态的扰动。我们还提出了自旋非破坏测量方法，非常适合原子电火花测量。(7)我们还提出并研究了一种观察自旋极化特殊分布的新方法——光学磁共振成像。(8) ）作为冷氦气对碱金属原子的新作用，我们发现了准分子和激基复合物的形成，其中氦原子粘附在激发态碱原子上。通过对这些激发态分子的光谱研究，我们可以确定它们的能量，包括振动能量，并可以获得形成的信息。