NEMS

Nano-Electro-Mechanical Systems (NEMS) are emerging as a transformative technology with applications in several sectors. As device scales shrink, NEMS stand out for their ability to investigate quantum fluids, with the potential to probe superfluid 3He’s properties due to their small dimensions and high resonant frequencies. We have developed NEMs with resonant frequencies up to 100 MHz, read out by a sensitive SQUID detection technique, uncovering a dynamic interplay between the NEMs’ motion and the SQUID’s state.

Topological phases of superfluid 3He

Nano-Electro-Mechanical Systems (NEMS) represent a new key disruptive technology providing potential solutions for research and industry across a wide range of sectors, from Quantum Information processing through physical sensors to biological sensor applications. As the dimensions of devices and structures reduce, new technologies and approaches are required. 

 

NEMs offer a new candidate system for probing the properties of quantum fluids. They can be nanofabricated with dimensions on the order of the size of the superfluid 3He cooper pair, resulting in resonant frequencies spanning a range from 0.1-100 MHz for beams and even higher frequencies for surface modes. A sub-10kHz wire with diameter 100 nm has been fabricated by top-down methods [1].

 

To exploit these properties at low temperatures the motion of the NEMs needs to be read-out with a low dissipation measurement technique. 

 

In prior work we have coupled NEMs devices to an extremely sensitive SQUID, Superconducting Quantum Interference Device. We performed measurements in the temperature range 10 mK to 8 K on resonators with quality factors of 1-100 million with a resonant frequency of order of 1 MHz. This work revealed a strong interplay between the motion of the beam and the state of the readout SQUID. 

 

SQUID readout of low frequency nanowires is currently under development as part of QUEST-DMC.

 

More widely our goals are to: 

  • Probe the nature of superfluid 3He by incorporating NEMs as local probes for topological mesoscopic superfluidity.
  • To cool a sub 100 MHz NEMs device into the quantum regime, to achieve a long coherence time quantum state.

References

  1. Long nanomechanical resonators with circular cross-section, Samuli Autti, Andrew Casey, Marie Connelly, Neda Darvishi, Paolo Franchini, James Gorman, Richard P. Haley, Petri J. Heikkinen, Ashlea Kemp, Elizabeth Leason, John March-Russell, Jocelyn Monroe, Theo Noble, George R. Pickett, Jonathan R. Prance, Xavier Rojas, Tineke Salmon, John Saunders, Jack Slater, Robert Smith, Michael D. Thompson, Stephen M. West, Luke Whitehead, Vladislav V. Zavjalov, Kuang Zhang, https://arxiv.org/abs/2311.02452