Nanomechanical vibrating wire resonator for phonon spectroscopy in Helium

TL;DR

This paper presents the development of a nanomechanical vibrating wire resonator for phonon spectroscopy in liquid helium, demonstrating phonon-induced resonance quenching and initial low-temperature operation.

Contribution

It introduces a novel nanoscopic resonator design for phonon excitation in helium and reports its successful operation at millikelvin temperatures.

Findings

Resonance quenching observed at 100 MHz in liquid helium at 4.2 K

First measurements of nano-resonator in ^3He/^4He mixture at 30 mK

Demonstration of phonon excitation detection using a nanomechanical resonator

Abstract

We demonstrate how to build a vibrating wire resonator for phonon excitation in liquid helium. The resonator is designed as a nanoscopic mechanically flexible beam machined out of a semiconductor/metal-hybrid. Quenching of the mechanical resonance around 100 MHz by phonon excitation in liquid ^4He at 4.2 K is shown. First measurements operating the nano-resonator in a dilution of ^3He/^4He at 30 mK are presented.