Quantum Nondemolition Squeezing of a Nanomechanical Resonator

TL;DR

This paper demonstrates how to achieve significant quantum squeezing of a nanomechanical resonator's position using continuous measurement and quantum feedback, advancing quantum control techniques for mechanical systems.

Contribution

It introduces a method for quantum nondemolition squeezing of a nanomechanical resonator via continuous measurement and feedback, extending quantum measurement concepts to nanoresonators.

Findings

Significant position squeezing below ground state achieved.

Quantum feedback prevents measurement-induced heating.

Proposed experimental verification method outlined.

Abstract

We show that the nanoresonator position can be squeezed significantly below the ground state level by measuring the nanoresonator with a quantum point contact or a single-electron transistor and applying a periodic voltage across the detector. The mechanism of squeezing is basically a generalization of quantum nondemolition measurement of an oscillator to the case of continuous measurement by a weakly coupled detector. The quantum feedback is necessary to prevent the ``heating'' due to measurement back-action. We also discuss a procedure of experimental verification of the squeezed state.