Advanced

Candidate for Laser Cooling of a Negative Ion : High-Resolution Photoelectron Imaging of Th

Tang, Rulin ; Si, Ran LU ; Fei, Zejie ; Fu, Xiaoxi ; Lu, Yuzhu ; Brage, Tomas LU ; Liu, Hongtao ; Chen, Chongyang and Ning, Chuangang (2019) In Physical Review Letters 123(20).
Abstract

Laser cooling is a well-established technique for the creation of ensembles of ultracold neutral atoms or positive ions. This ability has opened many exciting new research fields over the past 40 years. However, no negatively charged ions have been directly laser cooled because a cycling transition is very rare in atomic anions. Efforts of more than a decade currently have La- as the most promising candidate. We report on experimental and theoretical studies supporting Th- as a new promising candidate for laser cooling. The measured and calculated electron affinities of Th are, respectively, 4901.35(48) cm-1 and 4832 cm-1, or 0.607 690(60) and 0.599 eV, almost a factor of 2 larger than the previous theoretical value of 0.368 eV. The... (More)

Laser cooling is a well-established technique for the creation of ensembles of ultracold neutral atoms or positive ions. This ability has opened many exciting new research fields over the past 40 years. However, no negatively charged ions have been directly laser cooled because a cycling transition is very rare in atomic anions. Efforts of more than a decade currently have La- as the most promising candidate. We report on experimental and theoretical studies supporting Th- as a new promising candidate for laser cooling. The measured and calculated electron affinities of Th are, respectively, 4901.35(48) cm-1 and 4832 cm-1, or 0.607 690(60) and 0.599 eV, almost a factor of 2 larger than the previous theoretical value of 0.368 eV. The ground state of Th- is determined to be 6d37s2 F43/2e rather than 6d27s27p G45/2o. The consequence of this is that there are several strong electric dipole transitions between the bound levels arising from configurations 6d37s2 and 6d27s27p in Th-. The potential laser-cooling transition is S1/2o2↔F43/2e with a wavelength of 2.6 μm. The zero nuclear spin and hence lack of hyperfine structure in Th- reduces the potential complications in laser cooling as encountered in La-, making Th- a new and exciting candidate for laser cooling.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review Letters
volume
123
issue
20
article number
203002
publisher
American Physical Society
external identifiers
  • pmid:31809070
  • scopus:85075106064
ISSN
0031-9007
DOI
10.1103/PhysRevLett.123.203002
language
English
LU publication?
yes
id
825cc254-4653-47be-933b-fa920e932b02
date added to LUP
2019-11-29 08:24:13
date last changed
2021-01-12 04:05:11
@article{825cc254-4653-47be-933b-fa920e932b02,
  abstract     = {<p>Laser cooling is a well-established technique for the creation of ensembles of ultracold neutral atoms or positive ions. This ability has opened many exciting new research fields over the past 40 years. However, no negatively charged ions have been directly laser cooled because a cycling transition is very rare in atomic anions. Efforts of more than a decade currently have La- as the most promising candidate. We report on experimental and theoretical studies supporting Th- as a new promising candidate for laser cooling. The measured and calculated electron affinities of Th are, respectively, 4901.35(48) cm-1 and 4832 cm-1, or 0.607 690(60) and 0.599 eV, almost a factor of 2 larger than the previous theoretical value of 0.368 eV. The ground state of Th- is determined to be 6d37s2 F43/2e rather than 6d27s27p G45/2o. The consequence of this is that there are several strong electric dipole transitions between the bound levels arising from configurations 6d37s2 and 6d27s27p in Th-. The potential laser-cooling transition is S1/2o2↔F43/2e with a wavelength of 2.6 μm. The zero nuclear spin and hence lack of hyperfine structure in Th- reduces the potential complications in laser cooling as encountered in La-, making Th- a new and exciting candidate for laser cooling.</p>},
  author       = {Tang, Rulin and Si, Ran and Fei, Zejie and Fu, Xiaoxi and Lu, Yuzhu and Brage, Tomas and Liu, Hongtao and Chen, Chongyang and Ning, Chuangang},
  issn         = {0031-9007},
  language     = {eng},
  month        = {11},
  number       = {20},
  publisher    = {American Physical Society},
  series       = {Physical Review Letters},
  title        = {Candidate for Laser Cooling of a Negative Ion : High-Resolution Photoelectron Imaging of Th},
  url          = {http://dx.doi.org/10.1103/PhysRevLett.123.203002},
  doi          = {10.1103/PhysRevLett.123.203002},
  volume       = {123},
  year         = {2019},
}