Improved constraints on minimum length models with a macroscopic low loss phonon cavity

TL;DR

This paper enhances experimental constraints on minimum length theories by using a cryogenic quartz resonator, achieving three orders of magnitude improvement, and explores hybrid modes' sensitivity to quantum gravity effects.

Contribution

It introduces a novel experimental setup with a cryogenic quartz resonator to significantly tighten bounds on minimum length models and investigates hybrid electromechanical modes for GUP effects.

Findings

Three orders of magnitude improvement in GUP constraints.

Hybrid electromechanical modes are sensitive to GUP effects.

Cryogenic quartz resonator enhances measurement precision.

Abstract

Many theories that attempt to formulate a quantum description of gravity suggest the existence of a fundamental minimum length scale. A popular method for incorporating this minimum length is through a modification of the Heisenberg uncertainty principle known as the generalised uncertainty principle (GUP). Experimental tests of the GUP applied to composite systems can be performed by searching for the induced frequency perturbations of the modes of mechanical resonators, thus constraining the degree of minimum length in certain scenarios. In this work previous constraints made with mechanical resonators are improved upon by three orders of magnitude, via the utilisation of a cryogenic quartz bulk acoustic wave resonator. As well as purely mechanical resonant modes; hybrid electromechanical anti-resonant modes are investigated, and shown to be sensitive to the same GUP induced effects.