Can reactive coupling beat motional quantum limit of nano waveguides coupled to microdisk resonator

TL;DR

This paper demonstrates that reactive coupling in nano waveguides coupled to microdisk resonators can generate significant quantum squeezing, surpassing the standard quantum limit even at relatively high temperatures.

Contribution

It introduces a method to achieve quantum squeezing via dissipative reactive coupling, outperforming traditional approaches limited by motional quantum constraints.

Findings

Achieves 70-75% squeezing at 1-10 mK temperature.

Maximum squeezing with only 12 μW pump power at 1 mK.

Squeezing remains around 60% at 20 mK temperature.

Abstract

Dissipation is generally thought to affect the quantum nature of the system in an adverse manner, however we show that dissipatively coupled nano systems can be prepared in states which beat the standard quantum limit of the mechanical motion. We show that the reactive coupling between the waveguide and the microdisk resonator can generate the squeezing of the waveguide by injecting a quantum field and laser into the resonator through the waveguide. The waveguide can show about 70--75% of maximal squeezing for temperature about 1--10 mK. The maximum squeezing can be achieved with incident pump power of only 12 $\mu$W for a temperature of about 1 mK. Even for temperatures of 20 mK, achievable by dilution refrigerators, the maximum squeezing is about 60%.