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Microwave cavity-enhanced transduction for plug and play nanomechanics at room temperature.

Faust T, Krenn P, Manus S, Kotthaus JP, Weig EM - Nat Commun (2012)

Bottom Line: Furthermore, our approach constitutes an 'opto'-mechanical system in which backaction effects of the microwave field are employed to alter the effective damping of the resonators.In particular, cavity-pumped self-oscillation yields a linewidth of only 5 Hz.Thereby, an adjustement-free, all-integrated and self-driven nanoelectromechanical resonator array interfaced by just two microwave connectors is realised, which is potentially useful for applications in sensing and signal processing.

View Article: PubMed Central - PubMed

Affiliation: Center for NanoScience (CeNS) and Fakultät für Physik, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, München 80539, Germany.

ABSTRACT
Following recent insights into energy storage and loss mechanisms in nanoelectromechanical systems (NEMS), nanomechanical resonators with increasingly high quality factors are possible. Consequently, efficient, non-dissipative transduction schemes are required to avoid the dominating influence of coupling losses. Here we present an integrated NEMS transducer based on a microwave cavity dielectrically coupled to an array of doubly clamped pre-stressed silicon nitride beam resonators. This cavity-enhanced detection scheme allows resolving of the resonators' Brownian motion at room temperature while preserving their high mechanical quality factor of 290,000 at 6.6 MHz. Furthermore, our approach constitutes an 'opto'-mechanical system in which backaction effects of the microwave field are employed to alter the effective damping of the resonators. In particular, cavity-pumped self-oscillation yields a linewidth of only 5 Hz. Thereby, an adjustement-free, all-integrated and self-driven nanoelectromechanical resonator array interfaced by just two microwave connectors is realised, which is potentially useful for applications in sensing and signal processing.

No MeSH data available.


Cavity-induced damping and self-oscillation.Using a blue-detuned (red-detuned) cavity drive, the amplitude of the beam can be amplified (damped). This effect is controlled by the microwave power Pμw, as shown in a (blue squares: blue detuning, red triangles: red detuning) for the optimal Δopt of ±9 MHz. By increasing the microwave power to 23 dBm, the backaction gain caused by the blue-detuned cavity exceeds the intrinsic damping, and self-oscillation occurs. The respective power spectrum in b shows a linewidth reduced to 5 Hz.
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f4: Cavity-induced damping and self-oscillation.Using a blue-detuned (red-detuned) cavity drive, the amplitude of the beam can be amplified (damped). This effect is controlled by the microwave power Pμw, as shown in a (blue squares: blue detuning, red triangles: red detuning) for the optimal Δopt of ±9 MHz. By increasing the microwave power to 23 dBm, the backaction gain caused by the blue-detuned cavity exceeds the intrinsic damping, and self-oscillation occurs. The respective power spectrum in b shows a linewidth reduced to 5 Hz.

Mentions: The effective Q(Δ) in Fig. 3b clearly shows the expected behaviour: at negative detuning, the additional cavity-induced damping Γ(Δ) is positive, such that the effective damping exceeds the intrinsic value and Q(Δ) decreases, whereas at positive detuning the opposite occurs, with an optimal detuning of /Δopt/=9 MHz. Fitting the theoretical model (refs 27,28,29 and Supplementary Methods) to the data measured at several cavity drive powers allows to extract the average coupling factor . The backaction effect is independent of piezo-driven beam actuation as only the effective damping is changed. This is confirmed by repeating the experiment without piezo actuation (inset of Fig. 3b). A comparison between the weakly driven situation depicted in Fig. 3b and the Brownian motion in the inset only shows a significant increase of the noise in the latter case. Therefore, all measurements in Figs 3 and 4a (except the inset in Fig. 3b) were done with a weak piezo actuation of −70 dBm to operate with an improved signal to noise ratio.


Microwave cavity-enhanced transduction for plug and play nanomechanics at room temperature.

Faust T, Krenn P, Manus S, Kotthaus JP, Weig EM - Nat Commun (2012)

Cavity-induced damping and self-oscillation.Using a blue-detuned (red-detuned) cavity drive, the amplitude of the beam can be amplified (damped). This effect is controlled by the microwave power Pμw, as shown in a (blue squares: blue detuning, red triangles: red detuning) for the optimal Δopt of ±9 MHz. By increasing the microwave power to 23 dBm, the backaction gain caused by the blue-detuned cavity exceeds the intrinsic damping, and self-oscillation occurs. The respective power spectrum in b shows a linewidth reduced to 5 Hz.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3316880&req=5

f4: Cavity-induced damping and self-oscillation.Using a blue-detuned (red-detuned) cavity drive, the amplitude of the beam can be amplified (damped). This effect is controlled by the microwave power Pμw, as shown in a (blue squares: blue detuning, red triangles: red detuning) for the optimal Δopt of ±9 MHz. By increasing the microwave power to 23 dBm, the backaction gain caused by the blue-detuned cavity exceeds the intrinsic damping, and self-oscillation occurs. The respective power spectrum in b shows a linewidth reduced to 5 Hz.
Mentions: The effective Q(Δ) in Fig. 3b clearly shows the expected behaviour: at negative detuning, the additional cavity-induced damping Γ(Δ) is positive, such that the effective damping exceeds the intrinsic value and Q(Δ) decreases, whereas at positive detuning the opposite occurs, with an optimal detuning of /Δopt/=9 MHz. Fitting the theoretical model (refs 27,28,29 and Supplementary Methods) to the data measured at several cavity drive powers allows to extract the average coupling factor . The backaction effect is independent of piezo-driven beam actuation as only the effective damping is changed. This is confirmed by repeating the experiment without piezo actuation (inset of Fig. 3b). A comparison between the weakly driven situation depicted in Fig. 3b and the Brownian motion in the inset only shows a significant increase of the noise in the latter case. Therefore, all measurements in Figs 3 and 4a (except the inset in Fig. 3b) were done with a weak piezo actuation of −70 dBm to operate with an improved signal to noise ratio.

Bottom Line: Furthermore, our approach constitutes an 'opto'-mechanical system in which backaction effects of the microwave field are employed to alter the effective damping of the resonators.In particular, cavity-pumped self-oscillation yields a linewidth of only 5 Hz.Thereby, an adjustement-free, all-integrated and self-driven nanoelectromechanical resonator array interfaced by just two microwave connectors is realised, which is potentially useful for applications in sensing and signal processing.

View Article: PubMed Central - PubMed

Affiliation: Center for NanoScience (CeNS) and Fakultät für Physik, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, München 80539, Germany.

ABSTRACT
Following recent insights into energy storage and loss mechanisms in nanoelectromechanical systems (NEMS), nanomechanical resonators with increasingly high quality factors are possible. Consequently, efficient, non-dissipative transduction schemes are required to avoid the dominating influence of coupling losses. Here we present an integrated NEMS transducer based on a microwave cavity dielectrically coupled to an array of doubly clamped pre-stressed silicon nitride beam resonators. This cavity-enhanced detection scheme allows resolving of the resonators' Brownian motion at room temperature while preserving their high mechanical quality factor of 290,000 at 6.6 MHz. Furthermore, our approach constitutes an 'opto'-mechanical system in which backaction effects of the microwave field are employed to alter the effective damping of the resonators. In particular, cavity-pumped self-oscillation yields a linewidth of only 5 Hz. Thereby, an adjustement-free, all-integrated and self-driven nanoelectromechanical resonator array interfaced by just two microwave connectors is realised, which is potentially useful for applications in sensing and signal processing.

No MeSH data available.