Observation of electric-dipole transitions in the laser-cooling candidate Th- And its application for cooling antiprotons

Despite the fact that the laser-cooling method is a well-established technique to obtain ultracold neutral atoms and atomic cations, it has rarely if ever been applied to atomic anions due to the lack of suitable electric-dipole transitions. Efforts of more than a decade have until recently only resulted in La- as a promising anion candidate for laser cooling, but our previous work [Tang et al., Phys. Rev. Lett. 123, 203002 (2019)10.1103/PhysRevLett.123.203002] showed that Th- is also a potential candidate. Here we report on a combination of experimental and theoretical studies to determine the frequencies and rates, as well as branching ratios, for the relevant transitions in Th-. The resonant frequency of the laser-cooling transition is determined to be ν=123.455(30) THz [λ=2428.4(6)nm]. The transition rate is calculated as A=1.17×104s-1. Since the branching fraction to dark states is negligible, 1.47×10-10, this represents an ideal closed cycle in Th- for laser cooling. Furthermore, the zero nuclear spin of Th232 makes the cooling process possible in a Penning trap, which can be used to confine both antiprotons and Th- ions. The presented ion dynamics simulations show that the laser-cooled Th- anions can effectively cool antiprotons to a temperature around 10 mK.

Si, RanFudan University (författare)
Fei, ZejieShanghai Institute of Applied Physics, Chinese Academy of Sciences (författare)
Fu, XiaoxiTsinghua University (författare)
Lu, YuzhuTsinghua University (författare)
Brage, TomasLund University,Lunds universitet,Matematisk fysik,Fysiska institutionen,Institutioner vid LTH,Lunds Tekniska Högskola,Mathematical Physics,Department of Physics,Departments at LTH,Faculty of Engineering, LTH(Swepub:lu)nucl-tbr (författare)
Liu, HongtaoShanghai Institute of Applied Physics, Chinese Academy of Sciences (författare)
Chen, ChongyangFudan University (författare)
Ning, ChuangangTsinghua University (författare)
Tsinghua UniversityFudan University (creator_code:org_t)

Av författaren/redakt...: Tang, Rulin; Si, Ran; Fei, Zejie; Fu, Xiaoxi; Lu, Yuzhu; Brage, Tomas; visa fler...; Liu, Hongtao; Chen, Chongyang; Ning, Chuangang; visa färre...

Om ämnet

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.