Quantum Gas Microscope

In our lab, we are building a quantum gas microscope for ultracold molecules. This is an attempt to bring together our established work on the creation and coherent control of dipolar molecules, with the exquisite spatial resolution and control afforded by recent developments in high-resolution imaging of ultracold atoms in optical lattice

Quantum Simulation with Ultracold Molecules

Our experiment is designed to study large arrays of molecules in periodic potentials, which have been proposed as a highly versatile platform for studying quantum matter. Thanks to the long-range dipole-dipole interactions between heteronuclear molecules and coherent control over rotational states, many different aspects of quantum many-body physics can be studied. Condensed matter theorists propose using molecules in experiments like ours to study topological superfluidity, Chern insulating phases and many-body localisation phenomena, for a review see e.g. Bohn, J. L., et.al Science 357.6355 (2017). Our experiment aims to advance the techniques used to make and manipulate molecules and work towards the study of novel quantum phenomena in a regime beyond the reach of classical computation.

Overview

In our experiment we plan to form ultracold molecules of ⁸⁷Rb¹³³Cs molecules from ultracold mixtures of the two species. Atoms are cooled to ultracold temperatures in the main chamber using Degenerate Raman Sideband Cooling (1), and then loaded into an optical lattice which we can move to transfer them to a cell where we have a microscope.

Virtual Lab tour

Have a look around our lab!

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  Laser Cooling Table, here we have the lasers we use for cooling ⁸⁷Rb,¹³³Cs and ³⁹K. After passing through frequency control optics the light is sent to the vacuum table via optical fibre.

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  Science cell. In the middle of this photo you can see the glass cell and microscope objective which we use for quantum gas microscopy. The optics around the cell are used for evaporative cooling of the atoms and forming the optical lattice used for single site resolved imaging.

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  2D MOT. We cool atoms from room temperature into a cold beam using a pair of 2D+ MOTs, which cool atoms and trap atoms in two dimensions, and push them in the final dimension into the main chamber. By using a small amount of cooling in the push direction we can improve the loading of atoms into the 3D mot in the main section of the chamber.

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  STIRAP lasers. These lasers will be used to tranfer molecules between a weakly bound state and the absolute ground state using a coherent process which keeps the molecules cold. As they address transitions in the bi-alkali molecule we use a high finesse cavity under vaccum (metal cylinder in top right) as a frequency refernce.

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  Control system. The experiment is controlled using digital and analog signals from an FPGA. We monitor the progress of the cooling on the scope, and then ultimately measure the properties of the ultracold atoms from images which are processed in real time. Other signals from the lab, such as table temperature, laser noise etc are monitored using a time series database.

Lab publications

Papers

[4] Modulation Transfer Spectroscopy of the D1 Transition of Potassium: Theory and Experiment
Andrew D. Innes, Prosenjit Majumder, Heung-Ryoul Noh, and Simon L. Cornish
arXiv:2310.11327 (2023)

[3] Long distance optical conveyor-belt transport of ultracold ¹³³Cs and ⁸⁷Rb atoms
Alex J. Matthies, Jonathan M. Mortlock, Lewis A. McArd, Adarsh P. Raghuram, Andrew D. Innes, Philip D. Gregory, Sarah L. Bromley, and Simon L. Cornish
arXiv:2307.13382 (2023)

[2] A motorized rotation mount for the switching of an optical beam path in under 20 ms using polarization control
Adarsh P. Raghuram, Jonathan M. Mortlock, Sarah L. Bromley, and Simon L. Cornish
Rev. Sci. Instrum. 94, 063201 (2023)

[1] Measurement of the tune-out wavelength for ¹³³Cs at 880 nm
Apichayaporn Ratkata, Philip D. Gregory, Andrew D. Innes, Alex J. Matthies, Lewis A. McArd, Jonathan M. Mortlock, M. S. Safronova, Sarah L. Bromley, and Simon L. Cornish
Phys. Rev. A 104, 052813 (2021)

PhD theses

Jonathan Mortlock: Towards Quantum Gas Microscopy of Ultracold Molecules (2024)

Andrew Innes: Towards a novel platform for imaging molecules in an optical lattice (2023)

Alex Matthies: Optical Conveyor-Belt Transport of Cs and Rb Atoms (2023)