Study of superfluid 3He films with a micro-electro-mechanical device

27th International Conference on Low Temperature Physics

Zheng, P.^1 ; Jiang, W.G.^1 ; Barquist, C.S.^1 ; Chan, H.B.^2 ; Lee, Y.^1

Department of Physics, University of Florida, Gainesville

FL

32611, United States^1

Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong^2

关键词: Base temperature;    Mechanical resonance;    Microelectromechanical system (MEMS);    Orders of magnitude;    Quality factors;    Quasiparticles;    Resonance frequencies;    Thermal damping;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/568/1/012030/pdf
DOI  :  10.1088/1742-6596/568/1/012030

来源: IOP

【 摘 要 】

A micro-electro-mechanical system (MEMS) device with a 1.25 μm gap between a movable plate and the substrate was immersed in superfluid3He and cooled below 500 μK at 21.2 bar. Mechanical resonances of its shear motion were monitored on warming from the base temperature. Our preliminary results demonstrate increasing damping and decreasing resonance frequencies with temperature, consistent with a thermal damping model caused by thermal quasiparticles. The quality factor (Q) of the oscillator remains surprisingly low (Q 30) down to 0.2 T/Tc, about 4 orders of magnitude smaller than the value in vacuum at 4K. The average superfluid gap was determined to be significantly suppressed from the value in bulk at the corresponding pressure.