High-Q optomechanical GaAs nanomembranes

Abstract

We present a simple fabrication method for the realization of suspended GaAs nanomembranes for cavity quantum optomechanics experiments. GaAs nanomembranes with an area of 1.36 mm by 1.91 mm and a thickness of 160 nm are obtained by using a two-step selective wet-etching technique. The frequency noise spectrum reveals several mechanical modes in the kilohertz regime with mechanical Q-factors up to 2,300,000 at room temperature. The measured mechanical mode profiles agree well with a taut rectangular drumhead model. Our results show that GaAs nanomembranes provide a promising path towards quantum optical control of massive nanomechanical systems.Comment: 3 pages, 3 figure

Ultrahigh Q-frequency product for optomechanical disk resonators with a mechanical shield

“…Recent studies on GaAs disks reported Q Â f products between 10 11 and 10 12 in ambient conditions, 8,10 at the forefront of what has been demonstrated so far with GaAs based mechanical systems. [16][17][18] In this Letter we focus on mechanical dissipation and the Q Â f factor in GaAs disks, with an emphasis on clamping losses. By measuring and modeling the mechanical Q of disks of varying pedestal radius, we find that clamping loss is the dominant loss mechanism when these resonators sit on a simple central pedestal and are operated in vacuum at low temperature.…”

An electromechanical membrane resonator

“…5,16,18,19,22,23 It has also prevented development of the MMR for more practical applications. In addition, the large mass of MMRs typically 10 À11 -10 À9 kg and low frequency 15,16,[18][19][20] can also reduce their effectiveness in quantum cavity-optomechanical systems as well as limiting their sensitivity in mechanical detectors. 19 To address these drawbacks, a micron-sized MMR with a small effective mass $10 À13 kg operating at radio-frequencies, has been developed from a piezoelectric material which enables all electrical transduction of the mechanical motion.…”

“…[12][13][14] Recently, membrane-based mechanical resonators (MMRs) have garnered considerable attention as they enable high quality-factors, Qs. [15][16][17][18][19][20][21] In addition, they also have a large surface area compared to beams/cantilevers which not only makes them easier to use in optical architectures, [15][16][17][18][19] but it could also make them more responsive as detectors. 19 Consequently, the MMR has become a crucial element in many cavity-optomechanical systems, and it is also being rapidly developed for sensing applications.…”

“…However, to date most MMRs have been large passive structures operating at low frequencies with only optical control. 15,16,18,19 The lack of electrical control has limited the types of interactions that can be realized between optics and mechanics. 5,16,18,19,22,23 It has also prevented development of the MMR for more practical applications.…”

“…15,16,18,19 The lack of electrical control has limited the types of interactions that can be realized between optics and mechanics. 5,16,18,19,22,23 It has also prevented development of the MMR for more practical applications. In addition, the large mass of MMRs typically 10 À11 -10 À9 kg and low frequency 15,16,[18][19][20] can also reduce their effectiveness in quantum cavity-optomechanical systems as well as limiting their sensitivity in mechanical detectors.…”