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Journal ArticleDOI

Mechanical stiffening, bistability, and bit operations in a microcantilever

11 Nov 2010-Applied Physics Letters (American Institute of Physics)-Vol. 97, Iss: 19, pp 193107
TL;DR: In this paper, the authors investigated the nonlinear dynamics of microcantilevers and showed that at strong driving, the cantilever amplitude is bistable and suggested several applications for the bistability of the canticle.
Abstract: We investigate the nonlinear dynamics of microcantilevers. We demonstrate mechanical stiffening of the frequency response at large amplitudes, originating from the geometric nonlinearity. At strong driving the cantilever amplitude is bistable. We map the bistable regime as a function of drive frequency and amplitude, and suggest several applications for the bistable microcantilever, of which a mechanical memory is demonstrated.

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Citations
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Journal ArticleDOI
TL;DR: In this paper, the authors investigate mechanical mode coupling between the four fundamental vibrational modes of two doubly-clamped, high-Q silicon-nitride nanomechanical string resonators.
Abstract: We investigate mechanical mode coupling between the four fundamental flexural modes of two doubly-clamped, high-Q silicon-nitride nanomechanical string resonators. Strong mechanical coupling between the strings is induced by the strain mediated via a shared clamping point, engineered to increase the exchange of oscillatory energy. One of the resonators is controlled dielectrically, which results in strong coupling between its out-of-plane and in-plane flexural modes. We show both, inter-string out-of-plane-in-plane and 3-mode resonance of the four coupled fundamental vibrational modes of a resonator pair, giving rise to a simple and a multimode avoided crossing, respectively.

20 citations

Journal ArticleDOI
TL;DR: The phonon WG-localized resonator architecture demonstrates the viability of mechanical circuits for information processing applications.
Abstract: A phonon waveguide (WG) constructed via a one-dimensional array of mechanical resonators is used to access a localized mechanical resonator. This resonator plays the role of a memory node in which binary information can be written, stored, and read via the mobile mechanical excitations in the phonon WG. The phonon WG-localized resonator architecture demonstrates the viability of mechanical circuits for information processing applications.

19 citations

Journal ArticleDOI
TL;DR: Developing phonon waveguides, with a two-octave-wide phonon transmission band, in which mechanical four-wave-like mixing is demonstrated that enables the frequency of phonon waves to be converted over 1 MHz, which offers the broadband functionality that is essential to realising mechanical signal processors.
Abstract: The high-quality-factor mechanical resonator in electromechanical systems has facilitated dynamic control of phonons via parametric nonlinear processes and paved the development of mechanical logic-elements. However, the narrow spectral bandwidth of the resonating element constrains the available nonlinear phenomena thus limiting the functionality of the device as well as the switching speeds. Here we have developed phonon waveguides, with a two-octave-wide phonon transmission band, in which mechanical four-wave-like mixing is demonstrated that enables the frequency of phonon waves to be converted over 1 MHz. We harness this platform to execute multiple binary mechanical logic gates in parallel, via frequency division multiplexing in this broadband, where each gate can be independently reconfigured. The fidelity of the binary gates is verified via temporal measurements yielding eye diagrams which confirm the availability of high speed logic operations. The phonon waveguide architecture thus offers the broadband functionality that is essential to realising mechanical signal processors.

18 citations

Journal ArticleDOI
TL;DR: In this article, the phonon waveguide architecture is used to execute multiple binary mechanical logic gates in parallel, via frequency division multiplexing in a two-octave-wide phonon transmission band, where each gate can be independently reconfigured.
Abstract: The high-quality-factor mechanical resonator in electromechanical systems has facilitated dynamic control of phonons via parametric nonlinear processes and paved the development of mechanical logic-elements. However the resonating element with a narrow bandwidth limits the resultant operation speeds as well as constraining the availability of nonlinear phenomena to a narrow spectral range. To overcome these drawbacks we have developed phonon waveguides in which the mechanical analogue of four-wave-mixing is demonstrated that enables the frequency of phonon waves to be converted over 1 MHz. We harness this platform to execute multiple binary mechanical logic gates in parallel, via frequency division multiplexing in a two-octave-wide phonon transmission band, where each gate can be independently reconfigured. The fidelity of the binary gates is verified via temporal measurements yielding eye diagrams which confirm the availability of high speed logic operations. The phonon waveguide architecture thus offers the broadband functionality that is essential to realising mechanical signal processors.

17 citations

Journal ArticleDOI
TL;DR: In this article, the dynamical behavior of self-excited microcantilevers vibrating in viscous fluids is characterized experimentally and two complementary modelling approaches are proposed to explain and predict the behaviour of the closed-loop system.
Abstract: Microcantilevers are increasingly being used to create sensitive sensors for rheology and mass sensing at the micro- and nano-scale. When operating in viscous liquids, the low quality factor of such resonant structures, translating to poor signal-to-noise ratio, is often manipulated by exploiting feedback strategies. However, the presence of feedback introduces poorly-understood dynamical behaviours that may severely degrade the sensor performance and reliability. In this paper, the dynamical behaviour of self-excited microcantilevers vibrating in viscous fluids is characterized experimentally and two complementary modelling approaches are proposed to explain and predict the behaviour of the closed-loop system. In particular, the delay introduced in the feedback loop is shown to cause surprising non-linear phenomena consisting of shifts and sudden-jumps of the oscillation frequency. The proposed dynamical models also suggest strategies for controlling such undesired phenomena.

17 citations

References
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Journal ArticleDOI
15 Jul 2004-Nature
TL;DR: The long relaxation time of the measured signal suggests that the state of an individual spin can be monitored for extended periods of time, even while subjected to a complex set of manipulations that are part of the MRFM measurement protocol.
Abstract: Magnetic resonance imaging (MRI) is well known as a powerful technique for visualizing subsurface structures with three-dimensional spatial resolution. Pushing the resolution below 1 micro m remains a major challenge, however, owing to the sensitivity limitations of conventional inductive detection techniques. Currently, the smallest volume elements in an image must contain at least 10(12) nuclear spins for MRI-based microscopy, or 10(7) electron spins for electron spin resonance microscopy. Magnetic resonance force microscopy (MRFM) was proposed as a means to improve detection sensitivity to the single-spin level, and thus enable three-dimensional imaging of macromolecules (for example, proteins) with atomic resolution. MRFM has also been proposed as a qubit readout device for spin-based quantum computers. Here we report the detection of an individual electron spin by MRFM. A spatial resolution of 25 nm in one dimension was obtained for an unpaired spin in silicon dioxide. The measured signal is consistent with a model in which the spin is aligned parallel or anti-parallel to the effective field, with a rotating-frame relaxation time of 760 ms. The long relaxation time suggests that the state of an individual spin can be monitored for extended periods of time, even while subjected to a complex set of manipulations that are part of the MRFM measurement protocol.

1,379 citations

Journal Article
TL;DR: In this article, the authors reported the detection of an individual electron spin by magnetic resonance force microscopy (MRFM) and achieved a spatial resolution of 25nm in one dimension for an unpaired spin in silicon dioxide.
Abstract: Magnetic resonance imaging (MRI) is well known as a powerful technique for visualizing subsurface structures with three-dimensional spatial resolution. Pushing the resolution below 1 µm remains a major challenge, however, owing to the sensitivity limitations of conventional inductive detection techniques. Currently, the smallest volume elements in an image must contain at least 1012 nuclear spins for MRI-based microscopy, or 107 electron spins for electron spin resonance microscopy. Magnetic resonance force microscopy (MRFM) was proposed as a means to improve detection sensitivity to the single-spin level, and thus enable three-dimensional imaging of macromolecules (for example, proteins) with atomic resolution. MRFM has also been proposed as a qubit readout device for spin-based quantum computers. Here we report the detection of an individual electron spin by MRFM. A spatial resolution of 25 nm in one dimension was obtained for an unpaired spin in silicon dioxide. The measured signal is consistent with a model in which the spin is aligned parallel or anti-parallel to the effective field, with a rotating-frame relaxation time of 760 ms. The long relaxation time suggests that the state of an individual spin can be monitored for extended periods of time, even while subjected to a complex set of manipulations that are part of the MRFM measurement protocol.

1,192 citations

Journal ArticleDOI
01 Jan 1978
TL;DR: In this article, a set of mathematically consistent governing differential equations of motion describing the nonplanar, nonlinear dynamics of an inextensional beam is developed with the objective of retaining contributions due to nonlinear curvature as well as nonlinear inertia.
Abstract: This paper is divided into two parts. The authors’ purpose in Part I is to formulate a set of mathematically consistent governing differential equations of motion describing the nonplanar, nonlinear dynamics of an inextensional beam. The beam is assumed to undergo flexure about two principal axes and torsion. The equations are developed with the objective of retaining contributions due to nonlinear curvature as well as nonlinear inertia. A priori ordering assumptions are avoided as much as possible in the process. The equations are expanded to contain nonlinearities up to order three to facilitate comparison with analogous equations in the literature, and to render them amenable to the study of moderately large amplitude flexural-torsional oscillations by perturbation techniques. The utilization of the order-three equations in the analysis of nonlinear beam oscillations is the subject of Part II.

362 citations

Journal ArticleDOI
TL;DR: In this paper, the atomic force microscope (AFM) tip and sample are adjusted by pH and electrolytes to distribute the force applied to the AFM tip over a large sample area.

354 citations

Journal ArticleDOI
TL;DR: Pulsed microwave reflection measurements on nanofabricated Al junctions show that actual devices attain the performance predicted by theory, and the absence of on-chip dissipation is shown.
Abstract: We have constructed a new type of amplifier whose primary purpose is the readout of superconducting quantum bits. It is based on the transition of a rf-driven Josephson junction between two distinct oscillation states near a dynamical bifurcation point. The main advantages of this new amplifier are speed, high sensitivity, low backaction, and the absence of on-chip dissipation. Pulsed microwave reflection measurements on nanofabricated Al junctions show that actual devices attain the performance predicted by theory.

328 citations