Dark states of single NV centers in diamond unraveled by single shot NMR

The nitrogen-vacancy (NV) center in diamond is supposed to be a building block for quantum computing and nanometer scale metrology at ambient conditions. Therefore, precise knowledge of its quantum states is crucial. Here, we experimentally show that under usual operating conditions the NV exists in an equilibrium of two charge states (70% in the expected negative (NV-) and 30% in the neutral one (NV0)). Projective quantum non-demolition measurement of the nitrogen nuclear spin enables the detection even of the additional, optically inactive state. The nuclear spin can be coherently driven also in NV0 (T1 ~ 90 ms and T2 ~ 6 micro-s).Comment: 4 pages, 3 figure

The KATRIN Experiment

The KArlsruhe TRitium Neutrino mass experiment, KATRIN, aims to search for the mass of the electron neutrino with a sensitivity of 0.2 eV/c^2 (90% C.L.) and a detection limit of 0.35 eV/c^2 (5 sigma). Both a positive or a negative result will have far reaching implications for cosmology and the standard model of particle physics and will give new input for astroparticle physics and cosmology. The major components of KATRIN are being set up at the Karlsruhe Institut of Technology in Karlsruhe, Germany, and test measurements of the individual components have started. Data taking with tritium is scheduled to start in 2012.Comment: 3 pages, 1 figure, proceedings of the TAUP 2009 International Conference on Topics in Astroparticle and Underground Physics, to be published in Journal of Physics, Conference Serie

Variable accretion as a mechanism for brightness variations in T Tau S

(Note: this is a shortened version of the original A&A-style structured abstract). The physical nature of the strong photometric variability of T Tau Sa, the more massive member of the Southern "infrared companion" to T Tau, has long been debated. Intrinsic luminosity variations due to variable accretion were originally proposed but later challenged in favor of apparent fluctuations due to time-variable foreground extinction. In this paper we use the timescale of the variability as a diagnostic for the underlying physical mechanism. Because the IR emission emerging from Sa is dominantly thermal emission from circumstellar dust at <=1500K, we can derive a minimum size of the region responsible for the time-variable emission. In the context of the variable foreground extinction scenario, this region must be (un-) covered within the variability timescale, which implies a minimum velocity for the obscuring foreground material. If this velocity supercedes the local Kepler velocity we can reject foreground extinction as a valid variability mechanism. The variable accretion scenario allows for shorter variability timescales since the variations in luminosity occur on much smaller scales, essentially at the surface of the star, and the disk surface can react almost instantly on the changing irradiation with a higher or lower dust temperature and according brightness. We have detected substantial variations at long wavelengths in T Tau S: +26% within four days at 12.8 micron. We show that this short-term variability cannot be due to variable extinction and instead must be due to variable accretion. Using a radiative transfer model of the Sa disk we show that variable accretion can in principle also account for the much larger (several magnitude) variations observed on timescales of several years. For the long-term variability, however, also variable foreground extinction is a viable mechanism.Comment: 15 pages, 8 figures, Accepted for publication in Astronomy and Astrophysic

The Parker Instability in 3-D: Corrugations and Superclouds Along the Carina-Sagittarius Arm

Here we present three-dimensional MHD models for the Parker instability in a thick magnetized disk, including the presence of a spiral arm. The $B$-field is assumed parallel to the arm, and the model results are applied to the optical segment of the Carina-Sagittarius arm. The characteristic features of the undular and interchange modes are clearly apparent in the simulations. The undular mode creates large gas concentrations distributed along the arm. This results in a clear arm/inter-arm difference: the instability triggers the formation of large interstellar clouds inside the arms, but generates only small structures with slight density enhancements in the inter-arm regions. The resulting clouds are distributed in an antisymmetric way with respect to the midplane, creating an azimuthal corrugation along the arm. For conditions similar to those of the optical segment of the Carina-Sagittarius arm, it has a wavelength of about 2.4 kpc. This structuring can explain the origin of both HI superclouds and the azimuthal corrugations in spiral arms. The wavelength matches the corrugation length derived with the young stellar groups located in the optical segment of the Carina-Sagittarius arm. Keywords: Galaxy: kinematics and dynamics -- Galaxy: structure -- Instabilities -- ISM: clouds -- ISM: magnetic fields -- ISM: structure -- MHDComment: 29 pages, 12 figures, Latex, Accepted by the Astrophysical Journa

The depression in visual impairment trial (DEPVIT): trial design and protocol

&lt;b&gt;Background&lt;/b&gt; The prevalence of depression in people with a visual disability is high but screening for depression and referral for treatment is not yet an integral part of visual rehabilitation service provision. One reason for this may be that there is no good evidence about the effectiveness of treatments in this patient group. This study is the first to evaluate the effect of depression treatments on people with a visual impairment and co morbid depression.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods/design&lt;/b&gt; The study is an exploratory, multicentre, individually randomised waiting list controlled trial. Participants will be randomised to receive Problem Solving Therapy (PST), a ‘referral to the GP’ requesting treatment according to the NICE’s ‘stepped care’ recommendations or the waiting list arm of the trial. The primary outcome measure is change (from randomisation) in depressive symptoms as measured by the Beck’s Depression Inventory (BDI-II) at 6 months. Secondary outcomes include change in depressive symptoms at 3 months, change in visual function as measured with the near vision subscale of the VFQ-48 and 7 item NEI-VFQ at 3 and 6 months, change in generic health related quality of life (EQ5D), the costs associated with PST, estimates of incremental cost effectiveness, and recruitment rate estimation.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Discussion&lt;/b&gt; Depression is prevalent in people with disabling visual impairment. This exploratory study will establish depression screening and referral for treatment in visual rehabilitation clinics in the UK. It will be the first to explore the efficacy of PST and the effectiveness of NICE’s ‘stepped care’ approach to the treatment of depression in people with a visual impairment.&lt;p&gt;&lt;/p&gt

PILOT-SCALE TEST RESULTS OF A THIN FILM EVAPORATOR SYSTEM FOR MANAGEMENT OF LIQUID HIGH-LEVEL WASTES AT THE HANFORD SITE WASHINGTON USA -11364

A modular, transportable evaporator system, using thin film evaporative technology, is planned for deployment at the Hanford radioactive waste storage tank complex. This technology, herein referred to as a wiped film evaporator (WFE), will be located at grade level above an underground storage tank to receive pumped liquids, concentrate the liquid stream from 1.1 specific gravity to approximately 1.4 and then return the concentrated solution back into the tank. Water is removed by evaporation at an internal heated drum surface exposed to high vacuum. The condensed water stream will be shipped to the site effluent treatment facility for final disposal. This operation provides significant risk mitigation to failure of the aging 242-A Evaporator facility; the only operating evaporative system at Hanford maximizing waste storage. This technology is being implemented through a development and deployment project by the tank farm operating contractor, Washington River Protection Solutions (WRPS), for the Office of River Protection/Department of Energy (ORPIDOE), through Columbia Energy and Environmental Services, Inc. (Columbia Energy). The project will finalize technology maturity and install a system at one of the double-shell tank farms. This paper summarizes results of a pilot-scale test program conducted during calendar year 2010 as part of the ongoing technology maturation development scope for the WFE

Activated processes and Inherent Structure dynamics of finite-size mean-field models for glasses

We investigate the inherent structure (IS) dynamics of mean-field {\it finite-size} spin-glass models whose high-temperature dynamics is described in the thermodynamic limit by the schematic Mode Coupling Theory for super-cooled liquids. Near the threshold energy the dynamics is ruled by activated processes which induce a logarithmic slow relaxation. We show the presence of aging in both the IS correlation and integrated response functions and check the validity of the one-step replica symmetry breaking scenario in the presence of activated processes. Our work shows: 1) The violation of the fluctuation-dissipation theorem is given by the configurational entropy, 2) The intermediate time regime ($\log(t)\sim N$) in mean-field theory automatically includes activated processes opening the way to analytically investigate activated processes by computing corrections beyond mean-field.Comment: 8 pages, 3 postscript figures, EPL format, improved versio

Precise Neutron Magnetic Form Factors

Precise data on the neutron magnetic form factor G_{mn} have been obtained with measurements of the ratio of cross sections of D(e,e'n) and D(e,e'p) up to momentum transfers of Q^2 = 0.9 (GeV/c)^2. Data with typical uncertainties of 1.5% are presented. These data allow for the first time to extract a precise value of the magnetic radius of the neutron.Comment: 10 pages, 2 figures, submitted to Physics Letters

Observation of Bound Surface States in Grain Boundary Junctions of High Temperature Superconductors

We have performed a detailed study of the tunneling spectra of bicrystal grain boundary junctions (GBJs) fabricated from the HTS YBCO, BSCCO, LSCO, and NCCO. In all experiments the tunneling direction was along the CuO planes. With the exception of NCCO, for all materials a pronounced zero bias conductance peak was observed which decreases with increasing temperature and disappears at the critical temperature. These results can be explained by the presence of a dominating d-wave symmetry of the order parameter resulting in the formation of zero energy Andreev bound states at surfaces and interfaces of HTS. The absence of a ZBCP for NCCO is consistent with a dominating s-wave symmetry of the pair potential in this material. The observed nonlinear shift of spectral weight to finite energies by applying a magnetic field is in qualitative agreement with recent theoretical predictions.Comment: 4 pages, 4 figures, to be published in Phys. Rev.

Direct sampling of exponential phase moments of smoothed Wigner functions

We investigate exponential phase moments of the s-parametrized quasidistributions (smoothed Wigner functions). We show that the knowledge of these moments as functions of s provides, together with photon-number statistics, a complete description of the quantum state. We demonstrate that the exponential phase moments can be directly sampled from the data recorded in balanced homodyne detection and we present simple expressions for the sampling kernels. The phase moments are Fourier coefficients of phase distributions obtained from the quasidistributions via integration over the radial variable in polar coordinates. We performed Monte Carlo simulations of the homodyne detection and we demonstrate the feasibility of direct sampling of the moments and subsequent reconstruction of the phase distribution.Comment: RevTeX, 8 pages, 6 figures, accepted Phys. Rev.