Nanomechanical resonators for cryogenic research

TL;DR

This paper reports the fabrication and characterization of aluminium nanoelectromechanical resonators operated at cryogenic temperatures, demonstrating high Q-factors and sensitivity, with potential applications in superfluid helium research.

Contribution

The work introduces a fabrication process for aluminium nanoresonators and characterizes their linear and nonlinear behavior at cryogenic temperatures, highlighting their sensitivity to helium gas pressure.

Findings

Resonators achieved Q-values up to 4400 at 4.2 K.

Devices exhibit linear Lorentzian response at low amplitudes.

High sensitivity to $^4$He gas pressure was observed.

Abstract

Suspended aluminium nanoelectromechanical resonators have been fabricated, and the manufacturing process is described in this work. Device motion is driven and detected with a magnetomotive method. The resonance response has been measured at 4.2 K temperature in vacuum and low pressure $^4$He gas. At low oscillation amplitudes the resonance response is linear, producing Lorentzian line shapes, and Q-values up to 4400 have been achieved. At higher oscillation amplitudes the devices show nonlinear Duffing-like behavior. The devices are found to be extremely sensitive to pressure in $^4$He gas. Such device is a promising tool for studying properties of superfluid helium.