Matthias Imboden

High quality factor gigahertz frequencies in nanomechanical diamond resonators

We report actuation and detection of gigahertz-range resonance frequencies in nanocrystalline diamond mechanical resonators. High order transverse vibration modes are measured in coupled-beam resonators exhibiting frequencies up to 1.441GHz. The cantilever-array design of the resonators translates the gigahertz-range resonant motion of micron-long cantilever elements to the displacement of the central supporting structure. Use of nanocrystalline diamond further increases the frequency compared to single crystal silicon by a factor of 3. High clamping losses usually associated with micron-sized straight beams are suppressed in the periodic geometry of our resonators, allowing for high quality factors exceeding 20 000 above 500MHz.

Scaling of dissipation in megahertz-range micromechanical diamond oscillators

The authors report frequency and dissipation scaling laws for doubly clamped diamond resonators. The device lengths range from 10to19μm corresponding to frequency and quality-factor ranges of 17to66MHz and 600–2400, respectively. The authors find that the resonance frequency scales as 1∕L2 confirming the validity of the thin-beam approximation. The dominant dissipation comes from two sources: for the shorter beams, clamping loss is the dominant dissipation mechanism, while for the longer beams, surface losses provide a significant source of dissipation. The authors compare and contrast these mechanisms with other dissipation mechanisms to describe the data.

Electrostatically actuated silicon-based nanomechanical switch at room temperature

We demonstrate a silicon-based high-frequency nanomechanical device capable of switching controllably between two states at room temperature. The device uses a nanomechanical resonator with two distinct states in the hysteretic nonlinear regime. In contrast to prior work, we demonstrate room-temperature electrostatic actuation and sensing of the switching device with 100% fidelity by phase modulating the drive signal. This phase-modulated device can be used as a low-power, high-speed mechanical switch integrated on-chip with silicon circuitry.

Observation of nonlinear dissipation in piezoresistive diamond nanomechanical resonators by heterodyne down-mixing.

We report the observation of nonlinear dissipation in diamond nanomechanical resonators measured by an ultrasensitive heterodyne down-mixing piezoresistive detection technique. The combination of a hybrid structure as well as symmetry breaking clamps enables sensitive piezoresistive detection of multiple orthogonal modes in a diamond resonator over a wide frequency and temperature range. Using this detection method, we observe the transition from purely linear dissipation at room temperature to strongly nonlinear dissipation at cryogenic temperatures. At high drive powers and below liquid nitrogen temperatures, the resonant structure dynamics follows the Pol-Duffing equation of motion. Instead of using the broadening of the full width at half-maximum, we propose a nonlinear dissipation backbone curve as a method to characterize the strength of nonlinear dissipation in devices with a nonlinear spring constant.

Evidence of universality in the dynamical response of micromechanical diamond resonators at millikelvin temperatures

We report kelvin- to millikelvin-temperature measurements of dissipation and frequency shift in megahertz-range resonators fabricated from ultrananocrystalline diamond. Frequency shift

Nonlinear dissipation in diamond nanoelectromechanical resonators

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Electrothermally actuated tip-tilt-piston micromirror with integrated varifocal capability.

and dissipation

Atomic Calligraphy: The Direct Writing of Nanoscale Structures Using a Microelectromechanical System

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Energy measurement in nonlinearly coupled nanomechanical modes

demonstrate temperature dependence in the millikelvin range similar to that predicted by the glass model of tunneling two-level systems. The logarithmic temperature dependence of

Top-down nanomanufacturing

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