Imperial College London

ProfessorMichaelTarbutt

Faculty of Natural SciencesDepartment of Physics

Professor of Experimental Physics
 
 
 
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Contact

 

+44 (0)20 7594 7741m.tarbutt

 
 
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Location

 

207Blackett LaboratorySouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Jarvis:2018:10.1103/PhysRevA.98.043432,
author = {Jarvis, K and Sauer, B and Tarbutt, M},
doi = {10.1103/PhysRevA.98.043432},
journal = {Physical Review A},
title = {Characteristics of unconventional Rb magneto-optical traps},
url = {http://dx.doi.org/10.1103/PhysRevA.98.043432},
volume = {98},
year = {2018}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - We study several new magneto-optical trapping configurations in Rb. These unconventional MOTs all use type-II transitions, where the angular momentum of the ground state is greater than or equal to that of the excited state. Some use red-detuned light, and others blue-detuned light. The properties of these MOTs are strongly influenced by the balance between opposing Doppler and Sisyphus forces, and vary widely from one configuration to another. In the blue-detuned MOT, Sisyphus cooling dominates over Doppler heating for all relevant speeds and magnetic fields. We measure the capture velocity of this MOT as a function of intensity and detuning, finding a maximum of 3.8 ± 0.1 m/s. Atomic densities are particularly high in the blue-detuned MOT, and its lifetime is limited by collisions between the trapped atoms. We present measurements of the loss rate due to these ultracold collisions as a function of laser intensity and detuning. In the red-detuned MOTs, Sisyphus heating dominates at low speeds and Doppler cooling at higher speeds. Consequently, temperatures in the red-detuned MOTs are up to a thousand times higher than in the blue-detuned MOTs. One MOT forms large ring structures, with no density at the centre, showing how atoms driven towards a non-zero equilibrium speed remain trapped by orbiting around the centre. Another MOT demonstrates that magnetic mixing of the excited-state hyperfine levels can be an important mechanism in type-II MOTs.
AU - Jarvis,K
AU - Sauer,B
AU - Tarbutt,M
DO - 10.1103/PhysRevA.98.043432
PY - 2018///
SN - 1050-2947
TI - Characteristics of unconventional Rb magneto-optical traps
T2 - Physical Review A
UR - http://dx.doi.org/10.1103/PhysRevA.98.043432
UR - http://hdl.handle.net/10044/1/65159
VL - 98
ER -