Nanomechanical crystalline AlN resonators with high quality factors for quantum optoelectromechanics

Abstract

High-\Qm{} mechanical resonators are crucial for applications where low noise and long coherence time are required, as mirror suspensions, quantum cavity optomechanical devices, or nanomechanical sensors. Tensile strain in the material enables the use of dissipation dilution and strain engineering techniques, which increase the mechanical quality factor. These techniques have been employed for high-\Qm{} mechanical resonators made from amorphous materials and, recently, from crystalline materials such as InGaP, SiC, and Si. A strained crystalline film exhibiting substantial piezoelectricity expands the capability of high-\Qm{} nanomechanical resonators to directly utilize electronic degrees of freedom. In this work we realize nanomechanical resonators with \Qm{} up to $2.9\times 10^7$ made from tensile-strained \SI{290}{\nano\meter}-thick AlN, which is an epitaxially-grown crystalline material offering strong piezoelectricity. We demonstrate nanomechanical resonators that exploit dissipation dilution and strain engineering to reach a \Qf-product approaching $10^{13}$\,\SI{}{\hertz} at room temperature. We realize a novel resonator geometry, triangline, whose shape follows the Al-N bonds and offers a central pad that we pattern with a photonic crystal. This allows us to reach an optical reflectivity above 80\% for efficient coupling to out-of-plane light. The presented results pave the way for quantum optoelectromechanical devices at room temperature based on tensile-strained AlN.

References in corpus (11)

• Design of Optomechanical Cavities and Waveguides on a Simultaneous Bandgap Phononic-Photonic Crystal Slab
• Strained crystalline nanomechanical resonators with ultralow dissipation
• Ground State Cooling of an Ultracoherent Electromechanical System
• Fractal-like mechanical resonators with soft-clamped fundamental mode
• High-Strength Amorphous Silicon Carbide for Nanomechanics
• Centimeter-scale nanomechanical resonators with low dissipation
• Tensile strained $I{n}_{x}G{a}_{1-x}P$ membranes for cavity optomechanics
• High-Q trampoline resonators from strained crystalline InGaP for integrated free-space optomechanics
• Determining Young's modulus via the eigenmode spectrum of a nanomechanical string resonator
• Phononically shielded photonic-crystal mirror membranes for cavity quantum optomechanics
• Integrated microcavity optomechanics with a suspended photonic crystal mirror above a distributed Bragg reflector

Cited by in corpus (5)

• Thickness dependence of the mechanical properties of piezoelectric high-$Q_m$ nanomechanical resonators made from aluminium nitride
• High-$Q$ membrane resonators using ultra-high-stress crystalline TiN films
• Monolithic 4H-SiC nanomechanical resonators with high intrinsic quality factors
• Thermal analysis of GaN-based photonic membranes for optoelectronics
• Membrane phononic crystals for high-Qm mechanical defect modes in piezoelectric aluminum nitride