Silicon-nitride nanosensors toward room temperature quantum optomechanics

Abstract

Micro- and nanomechanical resonators play a prominent part in many sensing and signal processing platforms due to their capability to pervasively couple with a wide variety of physical systems. Particularly relevant is their embedding in advanced optomechanical setups, which has recently pioneered optically cooled mechanical oscillators toward the quantum regime. A frequently adopted experimental scheme exploits a thin, highly tensioned Si3N4 nanomembrane where the membrane’s vibrations are dispersively coupled to the optical mode of a Fabry–Pérot cavity. A significant effort has been done into realizing high-quality factor membranes, considering that low mechanical loss represents a benchmark to operate in the elusive quantum regime. In this article, we compare two state-of-the-art SiN resonators, realized exploiting the dilution of the material’s intrinsic dissipation and efficient solutions to fully isolate the membrane from the substrate. In particular, we examine and discuss the interplay between the edge and distributed dissipation and propose an analytical approach to evaluate the total intrinsic loss. Also, our analysis delves into the sensitivity of the devices to a point-like force and a uniform-density force field. These results provide meaningful guidelines for designing new ultra-coherent resonating devices.

Low Noise Opto-Electro-Mechanical Modulator for RF-to-Optical Transduction in Quantum Communications

“…The dilution parameter can be equivalently defined in terms of the flexural rigidity D of a film of a given material as λ = D/(σ 0 hR 2 ). The intrinsic losses can be decomposed into the edge and distributed losses [55,56], which depend upon the λ parameter linearly and quadratically, respectively. reservoir represented by the mechanical resonator cooled by the driven optical cavity mode.…”

“…Using the equation above and the definition of the dilution parameter for the SiN and the TiN films given above [55], we can rewrite Equation (1) as…”

Nanomechanical design strategy for single-mode optomechanical measurement

“…Besides applications, optomechanics allows fundamental studies into the quantum nature of macroscopic mechanical objects [19,20] using pulsed [21][22][23] or continuous [24][25][26][27][28] measurements, and investigation of possible decoherence mechanisms [29,30]. The class of nano-and micromechanical systems is particularly relevant in this field of study, thanks to the tremendous efforts toward ultracoherent resonators [31][32][33].…”

Nanomechanical Design Strategy for Single-Mode Optomechanical Measurement

“…The class of nano-and micro-mechanical systems is particularly relevant in this field of study, thanks to the tremendous efforts towards ultracoherent resonators [31][32][33].…”