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Showing papers on "Noise (electronics) published in 2007"


Book
15 Feb 2007
TL;DR: The Symbiosis of Noise and Order - Concluding Remarks as discussed by the authors is based on Probability Theory and Markovian Dichotomous Noise: An Exactly Soluble Colored-Noise Case.
Abstract: Elements of Probability Theory.- Stochastic Models of Environmental Fluctuations.- Markovian Diffusion Processes.- Stochastic Differential Equations.- Noise-Induced Nonequilibrium Phase Transitions.- Noise-Induced Transitions in Physics, Chemistry, and Biology.- External Colored Noise.- Markovian Dichotomous Noise: An Exactly Soluble Colored-Noise Case.- The Symbiosis of Noise and Order - Concluding Remarks.

669 citations


Journal ArticleDOI
TL;DR: Three distinct techniques exist for distributing an ultrastable frequency reference over optical fibers, and it is expected that the optical transfer to be similar in performance to the cw optical frequency transfer.
Abstract: Three distinct techniques exist for distributing an ultrastable frequency reference over optical fibers. For the distribution of a microwave frequency reference, an amplitude-modulated continuous wave (cw) laser can be used. Over kilometer-scale lengths this approach provides an instability at 1 s of ∼3×10−14 without stabilization of the fiber-induced noise and ∼1×10−14 with active noise cancellation. An optical frequency reference can be transferred by directly transmitting a stabilized cw laser over fiber and then disseminated to other optical and microwave regions using an optical frequency comb. This provides an instability at 1 s of 2×10−14 without active noise cancellation and 3×10−15 with active noise cancellation [Recent results reduce the instability at 1 s to 6×10−18.] Finally, microwave and optical frequency references can be simultaneously transmitted using an optical frequency comb, and we expect the optical transfer to be similar in performance to the cw optical frequency transfer. The insta...

402 citations


Journal ArticleDOI
TL;DR: For high feedback gain, the driven cantilever motion is found to suppress or "squash" the optical interferometer intensity noise below the shot noise level.
Abstract: We cool the fundamental mechanical mode of an ultrasoft silicon cantilever from a base temperature of 2.2 K down to 2.9+/-0.3 mK using active optomechanical feedback. The lowest observed mode temperature is consistent with limits determined by the properties of the cantilever and by the measurement noise. For high feedback gain, the driven cantilever motion is found to suppress or "squash" the optical interferometer intensity noise below the shot noise level.

386 citations


Journal ArticleDOI
TL;DR: In this paper, a Josephson parametric amplifier from a transmission line resonator whose inner conductor is made from a series of superconducting quantum interference device (SQUID) array is presented.
Abstract: The authors create a Josephson parametric amplifier from a transmission line resonator whose inner conductor is made from a series of superconducting quantum interference device (SQUID) array. By changing the magnetic flux through the SQUID loops, they are able to adjust the circuit’s resonance frequency and the center of the amplified band between 4 and 7.8GHz. They observe that the amplifier has gains as large as 28dB and infers that it adds less than twice the input vacuum noise.

381 citations


Journal ArticleDOI
03 Jun 2007
TL;DR: A broadband inductorless low-noise amplifier (LNA) design that utilizes simultaneous noise and distortion cancellation is presented and is demonstrated to have a minimum internal gain of 14.5 dB.
Abstract: A broadband inductorless low-noise amplifier (LNA) design that utilizes simultaneous noise and distortion cancellation is presented. Concurrent cancellation of the intrinsic third-order distortion from individual stages is exhibited with the common-gate and common-source cascade. The LNA is then limited by the second-order interaction between the common source and common gate stages, which is common in all cascade amplifiers. Further removal of this third-order distortion is achieved by incorporating a second-order-distortion-free circuit technique in the common gate stage. Implemented in 0.13 m CMOS technology, this LNA achieved 16 dBm in both the 900 MHz and 2 GHz bands. Measurements demonstrate that the LNA has a minimum internal gain of 14.5 dB, noise figure of 2.6 dB from 800 MHz to 2.1GHz while drawing 11.6 mA from 1.5 V supply voltage.

363 citations


Journal ArticleDOI
TL;DR: In this paper, a Josephson parametric amplifier from a transmission line resonator whose inner conductor is made from a series of series of SQUID arrays was presented. But the inner conductor was not made from the same material.
Abstract: We create a Josephson parametric amplifier from a transmission line resonator whose inner conductor is made from a series SQUID array. By changing the magnetic flux through the SQUID loops, we are able to adjust the circuit's resonance frequency and, consenquently, the center of the amplified band, between 4 and 7.8 GHz. We observe that the amplifier has gains as large as 28 dB and infer that it adds less than twice the input vacuum noise.

314 citations


Journal ArticleDOI
TL;DR: In this article, a technique for reducing the dielectric noise by curing polydimethylsiloxane (PDMS) on the nanopore support chip was presented, yielding an unprecedented signal-to-noise ratio when observing dsDNA translocation events and ssDNA probe capture for force spectroscopy applications.
Abstract: The electrical noise characteristics of ionic current through organic and synthetic nanopores have been investigated. Comparison to proteinaceous alpha-Hemolysin pores reveals two dominant noise sources in silicon nitride nanometre-scale pores: a high-frequency noise associated with the capacitance of the silicon support chip (dielectric noise), and a low-frequency current fluctuation with 1/ f α characteristics (flicker noise). We present a technique for reducing the dielectric noise by curing polydimethylsiloxane (PDMS) on the nanopore support chip. This greatly improves the performance of solid-state nanopore devices, yielding an unprecedented signal-to-noise ratio when observing dsDNA translocation events and ssDNA probe capture for force spectroscopy applications. (Some figures in this article are in colour only in the electronic version)

286 citations


Journal ArticleDOI
TL;DR: In this paper, a self-differencing technique was used to sense much weaker avalanches, which reduced the afterpulse noise and achieved a detection efficiency of 10.8% with an after-pulse probability of 6.16%.
Abstract: InGaAs avalanche photodiodes (APDs) are convenient for single photon detection in the near-infrared (NIR) including the fibre communication bands (1.31/1.55 $\mu$m). However, to suppress afterpulse noise due to trapped avalanche charge, they must be gated with MHz repetition frequencies, thereby severely limiting the count rate in NIR applications. Here we show gating frequencies for InGaAs-APDs well beyond 1 GHz. Using a self-differencing technique to sense much weaker avalanches, we reduce drastically afterpulse noise. At 1.25 GHz, we obtain a detection efficiency of 10.8% with an afterpulse probability of 6.16%. In addition, the detector features low jitter (55 ps) and a count rate of 100 MHz.

265 citations


Journal ArticleDOI
TL;DR: In this article, the authors measured noise in thin-film superconducting coplanar waveguide resonators and found that the ratio between the noise power in the phase and amplitude directions is large, in excess of 30 dB.
Abstract: The authors have measured noise in thin-film superconducting coplanar waveguide resonators. This noise appears entirely as phase noise, equivalent to a jitter of the resonance frequency. In contrast, amplitude fluctuations are not observed at the sensitivity of their measurement. The ratio between the noise power in the phase and amplitude directions is large, in excess of 30 dB. These results have important implications for resonant readouts of various devices such as detectors, amplifiers, and qubits. They suggest that the phase noise is due to two-level systems in dielectric materials.

223 citations


Journal ArticleDOI
TL;DR: In this paper, the authors showed that adding TiO2 to Ta2O5 in TaO5/SiO2 coatings reduces the internal friction and in addition present data confirming it reduces thermal noise.
Abstract: Reducing thermal noise from optical coatings is crucial to reaching the required sensitivity in next generation interferometric gravitational-wave detectors. Here we show that adding TiO2 to Ta2O5 in Ta2O5/SiO2 coatings reduces the internal friction and in addition present data confirming it reduces thermal noise. We also show that TiO2-doped Ta2O5/SiO2 coatings are close to satisfying the optical absorption requirements of second generation gravitational-wave detectors.

221 citations


Journal ArticleDOI
TL;DR: Simulations of the noise produced by randomly oriented defects with a density of 5x10(17) m(-2) yield 1/f noise magnitudes in good agreement with experiments.
Abstract: We propose a model for 1/f flux noise in superconducting devices (f is frequency). The noise is generated by the magnetic moments of electrons in defect states which they occupy for a wide distribution of times before escaping. A trapped electron occupies one of the two Kramers-degenerate ground states, between which the transition rate is negligible at low temperature. As a result, the magnetic moment orientation is locked. Simulations of the noise produced by a plausible density of randomly oriented defects yield 1/f noise magnitudes in good agreement with experiments.

Journal ArticleDOI
P. Reegen1
TL;DR: SigSpec as mentioned in this paper is based on an analytical solution of the probability that a DFT peak of a given amplitude does not arise from white noise in a non-equally spaced data set.
Abstract: Context. Identifying frequencies with low signal-to-noise ratios in time series of stellar photometry and spectroscopy, and measuring their amplitude ratios and peak widths accurately, are critical goals for asteroseismology. These are also challenges for time series with gaps or whose data are not sampled at a constant rate, even with modern Discrete Fourier Transform (DFT) software. Also the False-Alarm Probability introduced by Lomb and Scargle is an approximation which becomes less reliable in time series with longer data gaps.Aims. A rigorous statistical treatment of how to determine the significance of a peak in a DFT, called SigSpec, is presented here. SigSpec is based on an analytical solution of the probability that a DFT peak of a given amplitude does not arise from white noise in a non-equally spaced data set.Methods. The underlying Probability Density Function (PDF) of the amplitude spectrum generated by white noise can be derived explicitly if both frequency and phase are incorporated into the solution. In this paper, I define and evaluate an unbiased statistical estimator, the “spectral significance”, which depends on frequency, amplitude, and phase in the DFT, and which takes into account the time-domain sampling.Results. I also compare this estimator to results from other well established techniques and assess the advantages of SigSpec, through comparison of its analytical solutions to the results of extensive numerical calculations. According to those tests, SigSpec obtains as accurate frequency values as a least-squares fit of sinusoids to data, and is less susceptible to aliasing than the Lomb-Scargle Periodogram, other DFTs, and Phase Dispersion Minimization (PDM). I demonstrate the effectiveness of SigSpec with a few examples of ground- and space-based photometric data, illustratring how SigSpec deals with the effects of noise and time-domain sampling in determining significant frequencies.

Journal ArticleDOI
TL;DR: It is demonstrated that in addition to synchronization, clustering, or more generally coherence, always results from arbitrary initial conditions, irrespective of the details of the oscillators.
Abstract: We study synchronization properties of general uncoupled limit-cycle oscillators driven by common and independent Gaussian white noises. Using phase reduction and averaging methods, we analytically derive the stationary distribution of the phase difference between oscillators for weak noise intensity. We demonstrate that in addition to synchronization, clustering, or more generally coherence, always results from arbitrary initial conditions, irrespective of the details of the oscillators.

Journal ArticleDOI
Jiang Yang1, Yu Jin-Long1, Wang Yao-Tian1, Zhang Li-Tai1, Yang En-ze1 
TL;DR: In this paper, a dual-loop OEO scheme is reported, which utilizes a polarization-beam splitter and a polarization beam combiner to suppress the sidemodes in each single loop.
Abstract: A dual loop optoelectronic oscillator (OEO) is able to effectively suppress the sidemodes in each single loop. In this paper, a dual-loop OEO scheme is reported. By utilizing a polarization-beam splitter and a polarization-beam combiner, the two loops are directly joined in the optical domain without adding any active electrical device. The laser's phase-to-intensity noise is discussed. We present free-running experimental results, which show a phase noise of -109 dBc/Hz at 10kHz away from the carrier (12 GHz) and a Q value of 1010 with a sidemode suppression ratio of 60 dB, which is improved by 30-50dB in the experimental comparison. Meanwhile, the experimental comparison indicates that no significant noise is introduced by this configuration

Journal ArticleDOI
TL;DR: In this paper, the spontaneous relaxation of a qubit affects the fidelity of a continuous quantum non-demolition measurement of the initial state of the qubit, and it is shown that the predicted fidelity is a monotone increasing function of the measurement time.
Abstract: We study how the spontaneous relaxation of a qubit affects a continuous quantum nondemolition measurement of the initial state of the qubit. Given some noisy measurement record $\ensuremath{\Psi}$, we seek an estimate of whether the qubit was initially in the ground or excited state. We investigate four different measurement protocols, three of which use a linear filter (with different weighting factors) and a fourth which uses a full nonlinear filter that gives the theoretically optimal estimate of the initial state of the qubit. We find that relaxation of the qubit at rate $1∕{T}_{1}$ strongly influences the fidelity of any measurement protocol. To avoid errors due to this decay, the measurement must be completed in a time that decrease linearly with the desired fidelity while maintaining an adequate signal to noise ratio. We find that for the nonlinear filter the predicted fidelity, as expected, is always better than the linear filters and that the fidelity is a monotone increasing function of the measurement time. For example, to achieve a fidelity of 90%, the box car linear filter requires a signal to noise ratio of $\ensuremath{\sim}30$ in a time ${T}_{1}$, whereas the nonlinear filter only requires a signal to noise ratio of $\ensuremath{\sim}18$.

Journal ArticleDOI
TL;DR: The noise analysis and optimization of the DLNA accurately accounts for the impact of thermal noise of line terminations and all device noise sources of each CMOS cascode cell including flicker noise, correlated gate-induced noise and channel thermal noise on the overall noise figure.
Abstract: In this paper, the systematic design and analysis of a CMOS performance-optimized distributed low-noise amplifier (DLNA) comprising bandwidth-enhanced cascode cells will be presented. Each cascode cell employs an inductor between the common-source and common-gate devices to enhance the bandwidth, while reducing the high-frequency input-referred noise. The noise analysis and optimization of the DLNA accurately accounts for the impact of thermal noise of line terminations and all device noise sources of each CMOS cascode cell including flicker noise, correlated gate-induced noise and channel thermal noise on the overall noise figure. A three-stage performance-optimized wideband DLNA has been designed and fabricated in a 0.18-mum SiGe process, where only MOS transistors were utilized. Measurements of the test chip show a flat noise figure of 2.9 dB, a forward gain of 8 dB, and input and output return losses below -12 dB and -10 dB, respectively, across the 7.5 GHz UWB band. The circuit exhibits an average IIP3 of -3.55 dBm. The 872 mum times 872 mum DLNA chip consumes 12 mA of current from a 1.8-V DC voltage.

Journal ArticleDOI
TL;DR: A general approximate Fokker–Planck equation of a stochastic system is obtained that finds that the number of peaks in SPD and the reentrant transition between one peak and two peaks and then to one peak again in the curve of SNR depends on the parameter q, the delay time τ , and the noise correlation time τ 0.

Journal ArticleDOI
TL;DR: In this article, a detailed analysis of the stressing mechanisms for highly rugged low-noise GaN monolithic-microwave integrated-circuit amplifiers operated at extremely high input powers is presented.
Abstract: This paper presents a detailed analysis of the stressing mechanisms for highly rugged low-noise GaN monolithic-microwave integrated-circuit amplifiers operated at extremely high input powers. As an example, a low-noise amplifier (LNA) operating in the 3-7-GHz frequency band is used. A noise figure (NF) below 2.3 dB is measured from 3.5 to 7 GHz with NF<1.8 dB between 5-7 GHz. This device survived 33 dBm of available RF input power for 16 h without any change in low-noise performance. The stress mechanisms at high input powers are identified by systematic measurements of an LNA and a single high electron-mobility transistor in the frequency and time domains. It is shown that the gate dc current, which occurs due to self-biasing, is the most critical factor regarding survivability. A series resistance in the gate dc feed can reduce this gate current by feedback, and may be used to improve LNA ruggedness

Journal ArticleDOI
TL;DR: In this article, the authors describe a method for designing cryogenic silicon-germanium (SiGe) transistor low-noise amplifiers and report record microwave noise temperature, i.e., 2 K, measured at the module connector interface with a 50-Omega generator.
Abstract: This paper describes a method for designing cryogenic silicon-germanium (SiGe) transistor low-noise amplifiers and reports record microwave noise temperature, i.e., 2 K, measured at the module connector interface with a 50-Omega generator. A theory for the relevant noise sources in the transistor is derived from first principles to give the minimum possible noise temperature and optimum generator impedance in terms of dc measured current gain and transconductance. These measured dc quantities are then reported for an IBM SiGe BiCMOS-8HP transistor at temperatures from 295 to 15 K. The measured and modeled noise and gain for both a single-and two-transistor cascode amplifier in the 0.2-3-GHz range are then presented. The noise model is then combined with the transistor equivalent-circuit elements in a circuit simulator and the noise in the frequency range up to 20 GHz is compared with that of a typical InP HEMT.

Journal ArticleDOI
TL;DR: In this paper, the influence of random fluctuations in environmental parameters (e.g., nutrient input and rainfall) on the behavior of two simple bistable, ecological models with a single dynamical variable was studied.

01 Jan 2007
TL;DR: In this paper, the authors reported on the characterization of VDI's zerobias Schottky detectors and showed that under low power operation the detectors achieve a measured noise-equivalent power (NEP) of about 1.5x10 W/√Hz, even without signal modulation.
Abstract: Schottky barrier diodes can be used as direct detectors throughout the millimeterand submillimeterwave bands. When the diodes are optimized to have a low forward turn-on voltage, the detectors can achieve excellent frequency response and bandwidth, even with zero-bias. This paper reports on the characterization of VDI’s zerobias Schottky detectors. Responsivity typically ranges from 4,000 V/W at 100 GHz to 400 V/W at 900 GHz and each detector achieves good responsivity across the entire singlemoded bandwidth of the input rectangular waveguide. Under low power operation the detectors achieve a measured noise-equivalent-power (NEP) of about 1.5x10 W/√Hz, even without signal modulation. Such high sensitivity is expected for any zero-bias diode detector with high responsivity when there is no incident RF power; since only thermal noise can be generated under this condition. However, as the input power is increased, excess noise is generated. This noise typically has a 1/f power spectrum and is commonly known as flicker noise. Flicker noise becomes increasingly important as the input power is increased and signal modulation is generally required to achieve maximum sensitivity. The signal-to-noise of the VDI zero-bias detectors has been carefully measured as a function of input power and modulation rate. This data allows the user to understand the sensitivity of the detector under real operating conditions, and is therefore far more useful than the simple measurement of detector NEP with zero RF power, which is commonly quoted in the literature for new diode detector designs. Index Terms — Terahertz detectors, zero-bias detectors, noise-equivalent power, flicker noise.

Journal ArticleDOI
TL;DR: Mechanical amplification and noise squeezing in a nonlinear nanomechanical resonator driven by an intense pump near its dynamical bifurcation point, namely, the onset of Duffing bistability is studied.
Abstract: We study mechanical amplification and noise squeezing in a nonlinear nanomechanical resonator driven by an intense pump near its dynamical bifurcation point, namely, the onset of Duffing bistability. Phase sensitive amplification is achieved by a homodyne detection scheme, where the displacement detector's output, which has a correlated spectrum around the pump frequency, is down-converted by mixing with a local oscillator operating at the pump frequency with an adjustable phase. The down-converted signal at the mixer's output could be either amplified or deamplified, yielding noise squeezing, depending on the local oscillator phase.

Proceedings ArticleDOI
26 Dec 2007
TL;DR: Spectrum sensing in a very low SNR environment (less than -20 dB) is considered in this paper and the noise rejection property of the cyclostationary spectrum is made use.
Abstract: Spectrum sensing in a very low SNR environment (less than -20 dB) is considered in this paper. We make use of the noise rejection property of the cyclostationary spectrum. The sensing algorithms are based on measurement of the cyclic spectrum of the received signals. The statistics of the cyclic spectrum of the stationary white Gaussian process are fully analyzed for three measurement methods of the cyclic spectrum. The application to IEEE 802.22 WRAN is presented and the probability of false alarm is analytically derived. The operating characteristic curves for the sensing algorithms are determined from computer simulations using ATSC A/74 DTV signal captures as a test database.

Journal ArticleDOI
TL;DR: This work constructs a local model for the case in which rho is maximally entangled and p is at or below a certain bound, and extends the model to arbitrary rho, providing bounds on the resistance to noise of the nonlocal correlations of entangled states.
Abstract: We study the nonlocal properties of states resulting from the mixture of an arbitrary entangled state rho of two d-dimensional systems and completely depolarized noise, with respective weights p and 1-p. We first construct a local model for the case in which rho is maximally entangled and p at or below a certain bound. We then extend the model to arbitrary rho. Our results provide bounds on the resistance to noise of the nonlocal correlations of entangled states. For projective measurements, the critical value of the noise parameter p for which the state becomes local is at least asymptotically log(d) larger than the critical value for separability.

Journal ArticleDOI
TL;DR: Noise equivalent sensitivity at ppbv level as well as spectroscopic chemical analysis of a mixture of two broadband absorbers with overlapping absorption spectra were demonstrated.
Abstract: Detection of molecules with wide unresolved rotational-vibrational absorption bands is demonstrated by using Quartz Enhanced Photoacoustic Spectroscopy and an amplitude modulated, high power, thermoelectrically cooled quantum cascade laser operating at 8.4 μm in an external cavity configuration. The laser source exhibits single frequency tuning of 135 cm-1 with a maximum optical output power of 50 mW. For trace-gas detection of Freon 125 (pentafluoroethane) at 1208.62 cm-1 a normalized noise equivalent absorption coefficient of NNEA=2.64×10-9 cm-1∙W/Hz1/2 was obtained. Noise equivalent sensitivity at ppbv level as well as spectroscopic chemical analysis of a mixture of two broadband absorbers (Freon 125 and acetone) with overlapping absorption spectra were demonstrated.

Proceedings ArticleDOI
01 Dec 2007
TL;DR: This paper presents the first statistical model of Vt fluctuation (ΔVtcell) in a floating-gate flash memory due to random telegraph noise, and concludes that the impact of scaling is weaker than the widely-accepted 1/L effWw trend.
Abstract: This paper presents the first statistical model of Vt fluctuation (ΔVtcell) in a floating-gate flash memory due to random telegraph noise. It considers current-path percolation, which generates a large-amplitude-noise tail, caused by dopant induced surface potential non-uniformity It concludes that the impact of scaling is weaker than the widely-accepted 1/LeffWeff trend. 3-σ ΔVtcell is estimated to increase by 1.8x rather than ≫10x from 90 nm to 20 nm technology nodes.

Journal ArticleDOI
TL;DR: In this paper, the authors present a model of how noise scales with the number of multiple nondestructive reads sampling up the ramp of the James Webb Space Telescope (JWST).
Abstract: We describe how the James Webb Space Telescope (JWST) Near-Infrared Spectrograph's (NIRSpec) detectors will be read out, and present a model of how noise scales with the number of multiple nondestructive reads sampling up the ramp. We believe that this noise model, which is validated using real and simulated test data, is applicable to most astronomical near-infrared instruments. We describe some nonideal behaviors that have been observed in engineering-grade NIRSpec detectors, and demonstrate that they are unlikely to affect NIRSpec sensitivity, operations, or calibration. These include a HAWAII-2RG reset anomaly and random telegraph noise (RTN). Using real test data, we show that the reset anomaly is (1) very nearly noiseless and (2) can be easily calibrated out. Likewise, we show that large-amplitude RTN affects only a small and fixed population of pixels. It can therefore be tracked using standard pixel operability maps.

Journal ArticleDOI
TL;DR: In this paper, the Kumaresan-Tufts and matrix pencil methods were compared with nonlinear least-squares fitting methods to estimate ringdown parameters from ringdown signals after a binary black hole merger.
Abstract: The ringdown phase following a binary black hole merger is usually assumed to be well described by a linear superposition of complex exponentials (quasinormal modes). In the strong-field conditions typical of a binary black hole merger, nonlinear effects may produce mode coupling. Artificial mode coupling can also be induced by the black hole's rotation, if the radiation field is expanded in terms of spin-weighted spherical harmonics (rather than spin-weighted spheroidal harmonics). Observing deviations from the predictions of linear black hole perturbation theory requires optimal fitting techniques to extract ringdown parameters from numerical waveforms, which are inevitably affected by numerical error. So far, nonlinear least-squares fitting methods have been used as the standard workhorse to extract frequencies from ringdown waveforms. These methods are known not to be optimal for estimating parameters of complex exponentials. Furthermore, different fitting methods have different performance in the presence of noise. The main purpose of this paper is to introduce the gravitational wave community to modern variations of a linear parameter estimation technique first devised in 1795 by Prony: the Kumaresan-Tufts and matrix pencil methods. Using ``test'' damped sinusoidal signals in Gaussian white noise we illustrate the advantages of these methods, showing that they have variance and bias at least comparable to standard nonlinear least-squares techniques. Then we compare the performance of different methods on unequal-mass binary black hole merger waveforms. The methods we discuss should be useful both theoretically (to monitor errors and search for nonlinearities in numerical relativity simulations) and experimentally (for parameter estimation from ringdown signals after a gravitational wave detection).

Journal ArticleDOI
TL;DR: A Bayesian phase estimation strategy is explored to demonstrate that it is possible to achieve the standard quantum limit independently from the true value of the phase shift and specific assumptions on the noise of the interferometer.
Abstract: We study a Mach-Zehnder interferometer fed by a coherent state in one input port and vacuum in the other. We explore a Bayesian phase estimation strategy to demonstrate that it is possible to achieve the standard quantum limit independently from the true value of the phase shift and specific assumptions on the noise of the interferometer. We have been able to implement the protocol by using parallel operation of two photon-number-resolving detectors and multiphoton coincidence logic electronics at the output ports of a weakly illuminated Mach-Zehnder interferometer. This protocol is unbiased, saturates the Cramer-Rao phase uncertainty bound, and, therefore, is an optimal phase estimation strategy.

Journal ArticleDOI
TL;DR: In this paper, the authors experimentally study stochastic resonance in a nonlinear bistable nanomechanical doubly clamped beam resonator, which is capacitively excited by an adjacent gate electrode.
Abstract: The authors experimentally study stochastic resonance in a nonlinear bistable nanomechanical doubly clamped beam resonator, which is capacitively excited by an adjacent gate electrode. The resonator is tuned to its bistability region by an intense pump near a point of equal transition rates between its two metastable states. The pump is amplitude modulated, inducing modulation of the activation barrier between the states. When noise is added to the excitation, resonator’s displacement exhibits noise dependent amplification of the modulation signal. They measure resonator’s response in the time and frequency domains, the spectral amplification, and the statistical distribution of the jump time.