A Sub-kHz Mechanical Resonator Passively Cooled to 6 mK

Loek van Everdingen; Jaimy Plugge; Tim Fuchs; Guido van de Stolpe; Dalal Benali; Thijmen de Jong; Jasper Bijl; Wim Bosch; Tjerk Oosterkamp

doi:10.1103/jmyg-299x

arXiv · 2510.24199

A Sub-kHz Mechanical Resonator Passively Cooled to 6 mK

Loek van Everdingen·Jaimy Plugge·Tim Fuchs·Guido van de Stolpe·Dalal Benali·Thijmen de Jong·Jasper Bijl·Wim Bosch·Tjerk Oosterkamp

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Abstract

Highly coherent mechanical resonators are invaluable to ultrasensitive detection techniques by enabling detection of small forces. Studying mechanical resonators in a thermal equilibrium state at millikelvin temperatures provides a promising path to increase their coherence time. Here, we passively cool a 700 Hz massive (1.5 ng) mechanical cantilever down to 6.1(4) mK by means of nuclear demagnetization, as confirmed by detecting its thermal motion via a lock-in based detection scheme. At the lowest temperatures the thermal motion of the resonator is still clearly distinguishable from the background noise. Our data analysis confirms that at these temperatures the motion is still thermally distributed. These results pave the way for passive cooling low-frequency resonators to the sub-millikelvin regime, which would enable new tests of quantum mechanics and advances in ultrasensitive force detection.

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BibTeX RIS

Loek van Everdingen, Jaimy Plugge, Tim Fuchs, Guido van de Stolpe, Dalal Benali, Thijmen de Jong, Jasper Bijl, Wim Bosch, Tjerk Oosterkamp. 2026-02-19. A Sub-kHz Mechanical Resonator Passively Cooled to 6 mK. https://doi.org/10.1103/jmyg-299x

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