Observation and interpretation of motional sideband asymmetry in a quantum electro-mechanical device

Quantum electro-mechanical systems offer a unique opportunity to probe quantum noise properties in macroscopic devices, properties which ultimately stem from the Heisenberg Uncertainty Principle. A simple example of this is expected to occur in a microwave parametric transducer, where mechanical motion generates motional sidebands corresponding to the up and down frequency-conversion of microwave photons. Due to quantum vacuum noise, the rates of these processes are expected to be unequal. We measure this fundamental imbalance in a microwave transducer coupled to a radio-frequency mechanical mode, cooled near the ground state of motion. We also discuss the subtle origin of this imbalance: depending on the measurement scheme, the imbalance is most naturally attributed to the quantum fluctuations of either the mechanical mode or of the electromagnetic field

Quantum squeezing of motion in a mechanical resonator

As a result of the quantum, wave-like nature of the physical world, a harmonic oscillator can never be completely at rest. Even in the quantum ground state, its position will always have fluctuations, called the zero-point motion. Although the zero-point fluctuations are unavoidable, they can be manipulated. In this work, using microwave frequency radiation pressure, we both prepare a micron-scale mechanical system in a state near the quantum ground state and then manipulate its thermal fluctuations to produce a stationary, quadrature-squeezed state. We deduce that the variance of one motional quadrature is 0.80 times the zero-point level, or 1 dB of sub-zero-point squeezing. This work is relevant to the quantum engineering of states of matter at large length scales, the study of decoherence of large quantum systems, and for the realization of ultra-sensitive sensing of force and motion

Extracting the Mass Dependence and Quantum Numbers of Short-Range Correlated Pairs from A(e,e'p) and A(e,e'pp) Scattering

The nuclear mass dependence of the number of short-range correlated (SRC) proton-proton (pp) and proton-neutron (pn) pairs in nuclei is a sensitive probe of the dynamics of short-range pairs in the ground state of atomic nuclei. This work presents an analysis of electroinduced single-proton and two-proton knockout measurements off 12C, 27Al, 56Fe, and 208Pb in kinematics dominated by scattering off SRC pairs. The nuclear mass dependence of the observed A(e,e'pp)/12C(e,e'pp) cross-section ratios and the extracted number of pp- and pn-SRC pairs are much softer than the mass dependence of the total number of possible pairs. This is in agreement with a physical picture of SRC affecting predominantly nucleon-nucleon pairs in a nodeless relative-S state of the mean-field basis.Comment: 6 pages, 3 figure

Mechanically Detecting and Avoiding the Quantum Fluctuations of a Microwave Field

During the theoretical investigation of the ultimate sensitivity of gravitational wave detectors through the 1970's and '80's, it was debated whether quantum fluctuations of the light field used for detection, also known as photon shot noise, would ultimately produce a force noise which would disturb the detector and limit the sensitivity. Carlton Caves famously answered this question with "They do." With this understanding came ideas how to avoid this limitation by giving up complete knowledge of the detector's motion. In these back-action evading (BAE) or quantum non-demolition (QND) schemes, one manipulates the required quantum measurement back-action by placing it into a component of the motion which is unobserved and dynamically isolated. Using a superconducting, electro-mechanical device, we realize a sensitive measurement of a single motional quadrature with imprecision below the zero-point fluctuations of motion, detect both the classical and quantum measurement back-action, and demonstrate BAE avoiding the quantum back-action from the microwave photons by 9 dB. Further improvements of these techniques are expected to provide a practical route to manipulate and prepare a squeezed state of motion with mechanical fluctuations below the quantum zero-point level, which is of interest both fundamentally and for the detection of very weak forces

First Amendment and Land Use, in Recent Developments in Land Use, Planning, and Zoning

In the mid-1980s, the focus in this area of the law was on nuisance closures and license revocation actions affecting adult bookstores and other kinds of establishments where either obscenity or illicit sexual activities were taking place. In our last committee report focusing on the first amendment area we reported on those areas of the law in light of the Supreme Court\u27s decision in Arcara v. Cloud Books, Inc. Since then, there has been one important Fifth Circuit decision, FW/PBS Inc. v. City of Dallas, that the Supreme Court has agreed to review, with a decision expected in 1989. There have been two recent important federal court decisions involving the zoning of religious institutions and religious uses, and a number of significant federal and state court decisions applying the Supreme Court\u27s standards for assessing the constitutionality of sign regulations established in Metromedia, Inc. v. City of San Diego. But, by far the most important decision in the last year in this area of land-use law was the Supreme Court\u27s decision in City of Lakewood v. Plain Dealer Publishing Co., involving regulation of newspaper vending machines on public property

First Amendment and Land Use, in Recent Developments in Land Use, Planning, and Zoning

In the mid-1980s, the focus in this area of the law was on nuisance closures and license revocation actions affecting adult bookstores and other kinds of establishments where either obscenity or illicit sexual activities were taking place. In our last committee report focusing on the first amendment area we reported on those areas of the law in light of the Supreme Court\u27s decision in Arcara v. Cloud Books, Inc. Since then, there has been one important Fifth Circuit decision, FW/PBS Inc. v. City of Dallas, that the Supreme Court has agreed to review, with a decision expected in 1989. There have been two recent important federal court decisions involving the zoning of religious institutions and religious uses, and a number of significant federal and state court decisions applying the Supreme Court\u27s standards for assessing the constitutionality of sign regulations established in Metromedia, Inc. v. City of San Diego. But, by far the most important decision in the last year in this area of land-use law was the Supreme Court\u27s decision in City of Lakewood v. Plain Dealer Publishing Co., involving regulation of newspaper vending machines on public property

Globalization, Markups and U.S. Welfare

This paper is the first attempt to structurally estimate the impact of globalization on markups, and the effect of changing markups on welfare, in a monopolistic competition model. To achieve this, we work with a class of preferences that allow for endogenous markups and firm entry and exit that are especially convenient for empirical work – the translog preferences, with symmetry in substitution imposed across products. Between 1992 and 2005 we find the U.S. market experienced a series of changes that confirm a pro-competitive effect: import shares rose and U.S. firms exited, leading to an implied fall in markups, while product variety and welfare went up. We estimate the impacts of these effects on a national level, and find that U.S. welfare rose by as much as 0.86 percent between 1992 and 2005 as a result of these changes, with product variety contributing one-half of that total.

Determination of antimicrobial susceptibilities on infected urines without isolation

A method is described for the quick determination of the susceptibilities of various unidentified bacteria contained in an aqueous physiological fluid sample, particularly urine, to one or more antibiotics. A bacterial adenosine triphosphate (ATP) assay is carried out after the elimination of non-bacterial ATP to determine whether an infection exists. If an infection does exist, a portion of the sample is further processed, including subjecting parts of the portion to one or more antibiotics. Growth of the bacteria in the parts are determined, again by an ATP assay, to determine whether the unidentified bacteria in the sample are susceptible to the antibiotic or antibiotics under test

Preliminary indications of water film distribution and thickness on an airfoil in a water spray

A sensor for measuring water film thickness is evaluated. The test is conducted in a small flow apparatus with a 1 ft chord model wing in a water spray. Photographic and visual observations are made of the upper wing surface and film thickness is measured on the upper and lower wing surfaces. The performance of the sensor appears highly satisfactory, and where valid comparisons can be made, repeatable results are obtained

Radio frequency association of heteronuclear Feshbach molecules

We present a detailed analysis of the production efficiency of weakly bound heteronuclear KRb-Feshbach molecules using radio frequency association in a harmonic trap. The efficiency was measured in a wide range of temperatures, binding energies and radio frequencies. A comprehensive analytical model is presented, explaining the observed asymmetric spectra and achieving good quantitative agreement with the measured production rates. This model provides a deep understanding of the molecule association process and paves the way for future experiments which rely on Feshbach molecules e.g. for the production of deeply bound molecules.Comment: 5 pages, 4 figure