Damping of a microelectromechanical oscillator in turbulent superfluid He-4: A probe of quantized vorticity in the ultralow temperature regime

Article

关键词: QUARTZ TUNING FORK;    QUANTUM TURBULENCE;    VIBRATING-WIRE;    POTENTIAL FLOW;    VORTEX DYNAMICS;    MUTUAL FRICTION;    HELIUM;    LAMINAR;    DRAG;    TRANSITION;   

DOI  :  10.1103/PhysRevB.101.174513

来源: SCIE

【 摘 要 】

We report a comprehensive investigation of the effects of quantum turbulence and quantized vorticity in superfluid He-4 on the motion of a microelectromechanical systems (MEMS) resonator. We find that the MEMS is uniquely sensitive to quantum turbulence present in the fluid. To generate turbulence in the fluid, a quartz tuning fork (TF) is placed in proximity to the MEMS and driven at a large amplitude. We observe that at low velocity, the MEMS is damped by the turbulence, and that above a critical velocity, v(c) similar or equal to 5 mm s(-1), the turbulent damping is greatly reduced. We find that above v(c), the damping of the MEMS is reduced further for increasing velocity, indicating a velocity dependent coupling between the surface of the MEMS and the quantized vortices constituting the turbulence. We propose a model of the interaction between vortices in the fluid and the surface of the MEMS. The sensitivity of these devices to a small number of vortices and the almost unlimited customization of MEMS open the door to a more complete understanding of the interaction between quantized vortices and oscillating structures, which in turn provides a new route for the investigation of the dynamics of single vortices.

【 授权许可】

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