Levitated macroscopic rotors with 10 hours of free spin at room temperature

TL;DR

This paper demonstrates a room-temperature, diamagnetically levitated millimeter-scale rotor with ultra-low dissipation, enabling over 10 hours of free spin and high-precision gyroscopic measurements.

Contribution

It introduces a stable diamagnetic levitation method for large-scale rotors with exceptionally low damping at room temperature, surpassing previous micro-scale limitations.

Findings

Achieved a dissipation rate of 3.85 μHz at room temperature.

Spinning duration exceeds 10 hours without significant loss of angular momentum.

Developed a gyroscope with sensitivity of 6.5×10^{-3} °/s.

Abstract

Low-dissipation rotors with large angular momentum are essential for precision sensing and probing macroscopic quantum phenomena. To date, low dissipation can only be achieved for micro-scale rotors. Here, we report a diamagnetically levitated millimeter-scale rotor exhibiting a measured dissipation rate as low as $3.85\,\mu\mathrm{Hz}$ at room temperature, corresponding to a free spinning duration exceeding 10 hours. The rotor is levitated stably over an axisymmetric permanent magnet trap, and can be driven up to 930 RPM using contactless electrostatic actuation in high vacuum. Leveraging its low damping rate and large angular momentum, we realize a precision gyroscope with a measured sensitivity of $6.5 \times 10^{-3}\ \mathrm{^\circ/s}$ and an estimated thermal-limited stability of $5.7 \times 10^{-7}\ \mathrm{^\circ/\sqrt{h}}$. These results establish diamagnetic levitation as a promising room-temperature platform for high-performance gyroscopes.