Phase noise in a Duffing oscillator induced by quantum turbulence

We report a comprehensive investigation of the effects of quantum turbulence and quantized vorticity in superfluid $⁴\mathrm{He}$ at ultralow temperatures on a nonlinear microelectromechanical systems (MEMS) resonator which is uniquely sensitive to fluctuations of quantum turbulence. We observe that the phase noise of the MEMS is significantly increased in the presence of turbulence, while the noise in the amplitude channel is negligible in comparison. We formulated a model based on a fluctuating number of vortices pinned on the device to explain the observed noise. We also present measurements of the noise statistics and power spectra, providing insight into the dissipation mechanism of vortices at the micrometer scale in the ultraquantum regime. The high degree of customizability of MEMS oscillators coupled with their sensitivity to a small number of vortices lays the foundation for a more complete understanding of the interaction between quantized vortices and oscillating structures, and also offers a window into the dynamics of single vortices and small-scale fluctuations of quantum turbulence.