Characteristics of a magneto-optical trap of molecules
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Author(s)
Type
Journal Article
Abstract
We present the properties of a magneto-optical trap (MOT) of CaF
molecules. We study the process of loading the MOT from a decelerated bu er-gas-cooled beam, and how best to slow this molecular beam in order to capture the most molecules. We determine how the number of molecules, the photon scattering rate, the oscillation frequency, damping constant, temperature, cloud size and lifetime depend on the key parameters of the MOT, especially the intensity and detuning of the main cooling laser. We compare our results to analytical and numerical models, to the properties of standard atomic MOTs, and to MOTs of SrF molecules. We load up to 2 x 10⁴ molecules, and measure a maximum scattering rate of 2.5 x 10⁶ s⁻¹ per molecule, a maximum oscillation frequency of 100 Hz, a maximum damping constant of 500 s⁻¹, and a minimum MOT rms radius of 1.5 mm. A minimum temperature of 730 μK is obtained by ramping down the laser intensity to low values. The lifetime, typically about 100 ms, is consistent with a leak out of the cooling cycle with a branching ratio of about 6 x 10⁻⁶. The MOT has a capture velocity of about 11 m/s.
molecules. We study the process of loading the MOT from a decelerated bu er-gas-cooled beam, and how best to slow this molecular beam in order to capture the most molecules. We determine how the number of molecules, the photon scattering rate, the oscillation frequency, damping constant, temperature, cloud size and lifetime depend on the key parameters of the MOT, especially the intensity and detuning of the main cooling laser. We compare our results to analytical and numerical models, to the properties of standard atomic MOTs, and to MOTs of SrF molecules. We load up to 2 x 10⁴ molecules, and measure a maximum scattering rate of 2.5 x 10⁶ s⁻¹ per molecule, a maximum oscillation frequency of 100 Hz, a maximum damping constant of 500 s⁻¹, and a minimum MOT rms radius of 1.5 mm. A minimum temperature of 730 μK is obtained by ramping down the laser intensity to low values. The lifetime, typically about 100 ms, is consistent with a leak out of the cooling cycle with a branching ratio of about 6 x 10⁻⁶. The MOT has a capture velocity of about 11 m/s.
Date Issued
2017-11-23
Date Acceptance
2017-09-22
Citation
New Journal of Physics, 2017, 19
ISSN
1367-2630
Publisher
Institute of Physics (IoP) and Deutsche Physikalische Gesellschaft
Journal / Book Title
New Journal of Physics
Volume
19
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© 2017 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. Original content from this
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Sponsor
Engineering & Physical Science Research Council (EPSRC)
Commission of the European Communities
Engineering & Physical Science Research Council (E
Engineering and Physical Sciences Research Council
Grant Number
EP/I012044/1
320789
RF040529
EP/M027716/1
Subjects
Science & Technology
Physical Sciences
Physics, Multidisciplinary
Physics
magneto-optical trap
laser-cooled molecules
ultracold molecules
DIATOMIC MOLECULE
POLAR-MOLECULES
ATOMS
physics.atom-ph
02 Physical Sciences
Fluids & Plasmas
Publication Status
Published
Article Number
ARTN 113035