Pulsed excitation dynamics of an optomechanical crystal resonator near its quantum ground-state of motion

Using pulsed optical excitation and read-out along with single phonon counting techniques, we measure the transient back-action, heating, and damping dynamics of a nanoscale silicon optomechanical crystal cavity mounted in a dilution refrigerator at a base temperature of 11mK. In addition to observing a slow (~740ns) turn-on time for the optical-absorption-induced hot phonon bath, we measure for the 5.6GHz `breathing' acoustic mode of the cavity an initial phonon occupancy as low as 0.021 +- 0.007 (mode temperature = 70mK) and an intrinsic mechanical decay rate of 328 +- 14 Hz (mechanical Q-factor = 1.7x10^7). These measurements demonstrate the feasibility of using short pulsed measurements for a variety of quantum optomechanical applications despite the presence of steady-state optical heating.Comment: 16 pages, 6 figure

Optical coupling to nanoscale optomechanical cavities for near quantum-limited motion transduction

A significant challenge in the development of chip-scale cavity-optomechanical devices as testbeds for quantum experiments and classical metrology lies in the coupling of light from nanoscale optical mode volumes to conventional optical components such as lenses and fibers. In this work we demonstrate a high-efficiency, single-sided fiber-optic coupling platform for optomechanical cavities. By utilizing an adiabatic waveguide taper to transform a single optical mode between a photonic crystal zipper cavity and a permanently mounted fiber, we achieve a collection efficiency for intracavity photons of 52% at the cavity resonance wavelength of λ ≈ 1538 nm. An optical balanced homodyne measurement of the displacement fluctuations of the fundamental in-plane mechanical resonance at 3.3 MHz reveals that the imprecision noise floor lies a factor of 2.8 above the standard quantum limit (SQL) for continuous position measurement, with a predicted total added noise of 1.4 phonons at the optimal probe power. The combination of extremely low measurement noise and robust fiber alignment presents significant progress towards single-phonon sensitivity for these sorts of integrated micro-optomechanical cavities

Deadly \u27Toxins\u27: A National Empirical Study of Racial Bias and Future Dangerousness Determinations

Since the beginning of the modern Death Penalty Era, one of the most important—and fraught—areas of capital punishment has been the so-called “future dangerousness” determination, a threshold inquiry that literally rests the defendant’s life or death on jurors’ predictions of the future. An overwhelming majority of capital executions have occurred in jurisdictions that embrace the perceived legitimacy of the future dangerousness inquiry, despite its obvious flaws and potential connection to the age-old racial disparities that continue to plague capital punishment. This Article presents, and empirically tests, the hypothesis that jurors’ future dangerousness assessments cannot be separated from their racial and ethnic biases held against Black and Latino defendants. It does so by examining two pathways whereby future dangerousness judgments may function in inappropriately racialized ways: First, it studies the domain of implicit bias and investigates, using Implicit Association Tests (IATs) we designed, whether jurors implicitly and automatically associate future danger with Black and Latino men, and conversely, associate future safety with White men. Second, it considers the domain of explicit bias and measures whether jurors’ self-reported racial animus may function as a driving force in future dangerousness judgments. The results of the studies show that, indeed, both implicit and explicit biases are inexorably linked with future dangerous determinations. After presenting the studies in detail, the Article situates the findings within death penalty jurisprudence and concludes that future dangerousness can no longer pass constitutional muster as a mandatory or permissible factor in capital cases

Programming multiple protein patterns on a single DNA nanostructure

The ability to create assemblies of proteins with spacing on the nanometer scale has important implications for proteomics, biodetection, and self-assembly. Structural DNA nanotechnology has led to the creation of a variety of nanostructures which should be capable of serving as an addressable template for the creation of complex molecular assemblies. The goal of such systems is to be able to position proteins or other components in distinct patterns with precise spacing. These systems take advantage of the well-defined structure and spacing of DNA and use these properties to act as a template for secondary components in a bottom-up approach toward self-assembly. Previous work in this area has primarily focused on the use of chemical or structural modifications of the DNA template in order to attach or recruit proteins or nanoparticles. We have recently shown that a single polyamide-biotin conjugate is capable of binding to a DX array made from two tiles without any modification of the target DNA

Public Management in Political Institutions: Explaining Perceptions of White House Chief of Staff Influence

The notion that public managers influence organizational performance is common in public administration research. However, less is known about why some managers are better at influencing organizational performance than others. Furthermore, relatively few studies have systematically examined managerial influence and scholars have yet to investigate either quantitatively or systematically managerial influence in the White House. Utilizing original survey data collected from former White House officials who served in the Reagan, George H.W. Bush, and Clinton administrations, this study applies empirical public management theory to examine for the first time the key determinants that shape perceptions of chief of staff managerial influence. The findings demonstrate how several core concepts in public management theory help explain the dynamics that drive perceptions of managerial influence, thereby providing a new contribution to the literature on public management

A Unified Account of the Moral Standing to Blame

Recently, philosophers have turned their attention to the question, not when a given agent is blameworthy for what she does, but when a further agent has the moral standing to blame her for what she does. Philosophers have proposed at least four conditions on having “moral standing”: 1. One’s blame would not be “hypocritical”. 2. One is not oneself “involved in” the target agent’s wrongdoing. 3. One must be warranted in believing that the target is indeed blameworthy for the wrongdoing. 4. The target’s wrongdoing must some of “one’s business”. These conditions are often proposed as both conditions on one and the same thing, and as marking fundamentally different ways of “losing standing.” Here I call these claims into question. First, I claim that conditions (3) and (4) are simply conditions on different things than are conditions (1) and (2). Second, I argue that condition (2) reduces to condition (1): when “involvement” removes someone’s standing to blame, it does so only by indicating something further about that agent, viz., that he or she lacks commitment to the values that condemn the wrongdoer’s action. The result: after we clarify the nature of the non-hypocrisy condition, we will have a unified account of moral standing to blame. Issues also discussed: whether standing can ever be regained, the relationship between standing and our "moral fragility", the difference between mere inconsistency and hypocrisy, and whether a condition of standing might be derived from deeper facts about the "equality of persons"

Measuring Stellar Radial Velocities with a Dispersed Fixed-Delay Interferometer

We demonstrate the ability to measure precise stellar barycentric radial velocities with the dispersed fixed-delay interferometer technique using the Exoplanet Tracker (ET), an instrument primarily designed for precision differential Doppler velocity measurements using this technique. Our barycentric radial velocities, derived from observations taken at the KPNO 2.1 meter telescope, differ from those of Nidever et al. by 0.047 km/s (rms) when simultaneous iodine calibration is used, and by 0.120 km/s (rms) without simultaneous iodine calibration. Our results effectively show that a Michelson interferometer coupled to a spectrograph allows precise measurements of barycentric radial velocities even at a modest spectral resolution of R ~ 5100. A multi-object version of the ET instrument capable of observing ~500 stars per night is being used at the Sloan 2.5 m telescope at Apache Point Observatory for the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS), a wide-field radial velocity survey for extrasolar planets around TYCHO-2 stars in the magnitude range 7.6<V<12. In addition to precise differential velocities, this survey will also yield precise barycentric radial velocities for many thousands of stars using the data analysis techniques reported here. Such a large kinematic survey at high velocity precision will be useful in identifying the signature of accretion events in the Milky Way and understanding local stellar kinematics in addition to discovering exoplanets, brown dwarfs and spectroscopic binaries.Comment: 9 pages, 4 figures. Accepted for publication in Ap

Equations of State for Nonlinear Sigma-Models II: Relations between Resummation Schemes, and Crossover Phenomena

It is shown how a recent method to systematically extrapolate and resum the loop expansion for nonlinear sigma-models is related to solutions of the renormalization group equation. This relation is used to generalize the explicit equations of state obtained previously to models which display crossover phenomena. As an example we discuss Wegner's localization model and consider the crossover from symplectic to unitary symmetry.Comment: 14pp., REVTeX, 1 figur