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Feshbach Spectroscopy of Cs Atom Pairs in Optical Tweezers

Brooks, R.V.; Guttridge, A.; Frye, Matthew D.; Ruttley, D.K.; Spence, S.; Hutson, Jeremy M.; Cornish, Simon L.

Feshbach Spectroscopy of Cs Atom Pairs in Optical Tweezers Thumbnail


R.V. Brooks

A. Guttridge

Matthew D. Frye

D.K. Ruttley

S. Spence


We prepare pairs of 133Cs atoms in a single optical tweezer and perform Feshbach spectroscopy for collisions of atoms in the states (f = 3, mf = ±3). We detect enhancements in pair loss using a detection scheme where the optical tweezers are repeatedly subdivided. For atoms in the state (3, −3), we identify resonant features by performing inelastic loss spectroscopy. We carry out coupled-channel scattering calculations and show that at typical experimental temperatures the loss features are mostly centred on zeroes in the scattering length, rather than resonance centres. We measure the number of atoms remaining after a collision, elucidating how the different loss processes are influenced by the tweezer depth. These measurements probe the energy released during an inelastic collision, and thus give information on the states of the collision products. We also identify resonances with atom pairs prepared in the absolute ground state (f = 3, mf = 3), where two-body radiative loss is engineered by an excitation laser blue-detuned from the Cs D2 line. These results demonstrate optical tweezers to be a versatile tool to study two-body collisions with number-resolved detection sensitivity.


Brooks, R., Guttridge, A., Frye, M. D., Ruttley, D., Spence, S., Hutson, J. M., & Cornish, S. L. (2022). Feshbach Spectroscopy of Cs Atom Pairs in Optical Tweezers. New Journal of Physics, 24, Article 113051.

Journal Article Type Article
Acceptance Date Oct 13, 2022
Online Publication Date Dec 12, 2022
Publication Date 2022
Deposit Date Apr 20, 2022
Publicly Available Date Dec 19, 2022
Journal New Journal of Physics
Publisher IOP Publishing
Peer Reviewed Peer Reviewed
Volume 24
Article Number 113051
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Copyright Statement
Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

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