Active stabilization of kilogauss magnetic fields to the ppm level for magnetoassociation on ultranarrow Feshbach resonances

Mateusz Borkowski; Lukas Reichsöllner; Premjith Thekkeppatt; Vincent Barbé; Tijs van Roon; Klaasjan van Druten; Florian Schreck

doi:10.1063/5.0143825

arXiv · 2303.13682

Active stabilization of kilogauss magnetic fields to the ppm level for magnetoassociation on ultranarrow Feshbach resonances

Mateusz Borkowski·Lukas Reichsöllner·Premjith Thekkeppatt·Vincent Barbé·Tijs van Roon·Klaasjan van Druten·Florian Schreck

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Abstract

Feshbach association of ultracold molecules using narrow resonances requires exquisite control of the applied magnetic field. Here we present a magnetic field control system to deliver magnetic fields of over 1000 G with ppm-level precision integrated into an ultracold-atom experimental setup. We combine a battery-powered current-stabilized power supply with active feedback stabilization of the magnetic field using fluxgate magnetic field sensors. As a real-world test we perform microwave spectroscopy of ultracold Rb atoms and demonstrate an upper limit on our magnetic field stability of 2.4(3) mG at 1050 G [2.3(3) ppm relative] as determined from the spectral feature.

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Mateusz Borkowski, Lukas Reichsöllner, Premjith Thekkeppatt, Vincent Barbé, Tijs van Roon, Klaasjan van Druten, Florian Schreck. 2023-03-23. Active stabilization of kilogauss magnetic fields to the ppm level for magnetoassociation on ultranarrow Feshbach resonances. https://doi.org/10.1063/5.0143825

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