High-Q trampoline resonators from strained crystalline InGaP for integrated free-space optomechanics

Abstract

Tensile-strained materials have been used to fabricate nano- and micromechanical resonators with ultra-low mechanical dissipation in the kHz to MHz frequency range. These mechanical resonators are of particular interest for force sensing applications and quantum optomechanics at room temperature. Tensile-strained crystalline materials that are compatible with epitaxial growth of heterostructures would thereby allow realizing monolithic free-space optomechanical devices, which benefit from stability, ultra-small mode volumes, and scalability. In our work, we demonstrate string- and trampoline resonators made from tensile-strained InGaP, which is a crystalline material that can be epitaxially grown on an AlGaAs heterostructure. The strain of the InGaP layer is defined via its Ga content when grown on (Al,Ga)As. In our case, we realize devices with a stress of up to 470\,MPa along the $[110]$ crystal direction. We characterize the mechanical properties of the suspended InGaP devices, such as anisotropic stress, yield strength, and intrinsic quality factor. We find that the latter degrades over time. We reach mechanical quality factors surpassing $10^7$ at room temperature with a $Q\cdot f$-product as high as $7\cdot 10^{11}$Hz with trampoline-shaped micromechanical resonators, which exploit strain engineering to dilute mechanical dissipation. The large area of the suspended trampoline resonator allows us to pattern a photonic crystal to engineer its out-of-plane reflectivity in the telecom band, which is desired for efficient signal transduction of mechanical motion to light. Stabilization of the intrinsic quality factor together with a further reduction of mechanical dissipation through hierarchical clamping or machine learning-based optimization methods paves the way for integrated free-space quantum optomechanics at room temperature in a crystalline material platform.

close to published version, added paragraph about future improvements in Appendix; 16 pages incl. appendix, 13 figures

References in corpus (6)

• Centimeter-scale suspended photonic crystal mirrors
• Tensile strained $I{n}_{x}G{a}_{1-x}P$ membranes for cavity optomechanics
• 2D photonic-crystal optomechanical nanoresonator
• 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
• Universal length dependence of tensile stress in nanomechanical string resonators

Cited by in corpus (14)

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• High-Q trampoline resonators from strained crystalline InGaP for integrated free-space optomechanics
• Integrated microcavity optomechanics with a suspended photonic crystal mirror above a distributed Bragg reflector
• Degeneracy-breaking and Long-lived Multimode Microwave Electromechanical Systems Enabled by Cubic Silicon-Carbide Membrane Crystals
• Nanomechanical crystalline AlN resonators with high quality factors for quantum optoelectromechanics
• Quasibound states in the continuum in photonic-crystal-based optomechanical microcavities
• Thickness dependence of the mechanical properties of piezoelectric high-$Q_m$ nanomechanical resonators made from aluminium nitride
• Dissipative and dispersive cavity optomechanics with a frequency-dependent mirror
• Magnetic Trampoline Resonators from (La,Sr)MnO3 Single-Crystal Thin Films
• High-$Q$ membrane resonators using ultra-high-stress crystalline TiN films
• Monolithic 4H-SiC nanomechanical resonators with high intrinsic quality factors
• Membrane phononic crystals for high-Qm mechanical defect modes in piezoelectric aluminum nitride