Magnetic cooling and vibration isolation of a sub-kHz mechanical resonator

Abstract

We report recent progress towards the realization of a sub-mK, low-vibration environment at the bottom stage of a dry dilution refrigerator for use in mechanical tests of quantum mechanics. Using adiabatic nuclear demagnetization, we have cooled a silicon cantilever force sensor to $T\approx 1$ mK. The temperature of the tip-holder of the cantilever chip was determined via a primary magnetic flux noise thermometer. The quality factor of the cantilever continues to increase with decreasing temperature, reaching $Q\approx 4\cdot 10^4$ at $2$ mK. To demonstrate that the vibration isolation is not compromised, we report the detection of the thermal motion of the cantilever down to $T\approx 20$ mK, only limited by the coupling to the SQUID readout circuit. We discuss feasible improvements that will allow us to probe unexplored regions of the parameter space of continuous spontaneous localization models.

Submission to the special issue "Mechanical Resonators at Low Temperatures" in Journal of Low Temperature Physics

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Cited by in corpus (5)

• First Search for Ultralight Dark Matter Using a Magnetically Levitated Particle
• Remote sensing of a levitated superconductor with a flux-tunable microwave cavity
• Mechanical Sensors for Ultraheavy Dark Matter Searches via Long-range Forces
• Massive quantum superpositions using magneto-mechanics
• A Sub-kHz Mechanical Resonator Passively Cooled to 6 mK