Generation of Squeezed States of Nanomechanical Resonators by Reservoir Engineering

TL;DR

This paper demonstrates how to generate and detect squeezed states in a nanomechanical resonator using reservoir engineering with a bichromatic microwave coupling to a charge qubit, enabling quantum state tomography.

Contribution

It introduces a method to produce and measure squeezed states in nanomechanical resonators via reservoir engineering with a charge qubit.

Findings

Achieved noise reduction in one quadrature by a factor of 0.5 - 0.2.

Demonstrated detection of squeezed states through charge qubit measurements.

Outlined a protocol for quantum state tomography of the resonator.

Abstract

An experimental demonstration of a non-classical state of a nanomechanical resonator is still an outstanding task. In this paper we show how the resonator can be cooled and driven into a squeezed state by a bichromatic microwave coupling to a charge qubit. The stationary oscillator state exhibits a reduced noise in one of the quadrature components by a factor of 0.5 - 0.2. These values are obtained for a 100 MHz resonator with a Q-value of 10$^4$ to 10$^5$ and for support temperatures of T $\approx$ 25 mK. We show that the coupling to the charge qubit can also be used to detect the squeezed state via measurements of the excited state population. Furthermore, by extending this measurement procedure a complete quantum state tomography of the resonator state can be performed. This provides a universal tool to detect a large variety of different states and to prove the quantum nature of a nanomechanical oscillator.