Integrated Diamond Optics for Single Photon Detection

Optical detection of single defect centers in the solid state is a key element of novel quantum technologies. This includes the generation of single photons and quantum information processing. Unfortunately the brightness of such atomic emitters is limited. Therefore we experimentally demonstrate a novel and simple approach that uses off-the-shelf optical elements. The key component is a solid immersion lens made of diamond, the host material for single color centers. We improve the excitation and detection of single emitters by one order of magnitude, as predicted by theory.Comment: 10 pages, 3 figure

Global Response to Local Ionospheric Mass Ejection

We revisit a reported "Ionospheric Mass Ejection" using prior event observations to guide a global simulation of local ionospheric outflows, global magnetospheric circulation, and plasma sheet pressurization, and comparing our results with the observed global response. Our simulation framework is based on test particle motions in the Lyon-Fedder-Mobarry (LFM) global circulation model electromagnetic fields. The inner magnetosphere is simulated with the Comprehensive Ring Current Model (CRCM) of Fok and Wolf, driven by the transpolar potential developed by the LFM magnetosphere, and includes an embedded plasmaspheric simulation. Global circulation is stimulated using the observed solar wind conditions for the period 24-25 Sept 1998. This period begins with the arrival of a Coronal Mass Ejection, initially with northward, but later with southward interplanetary magnetic field. Test particles are launched from the ionosphere with fluxes specified by local empirical relationships of outflow to electrodynamic and particle precipitation imposed by the MIlD simulation. Particles are tracked until they are lost from the system downstream or into the atmosphere, using the full equations of motion. Results are compared with the observed ring current and a simulation of polar and auroral wind outflows driven globally by solar wind dynamic pressure. We find good quantitative agreement with the observed ring current, and reasonable qualitative agreement with earlier simulation results, suggesting that the solar wind driven global simulation generates realistic energy dissipation in the ionosphere and that the Strangeway relations provide a realistic local outflow description

Products of motor burnout. Final report

The Montreal Protocol of 1987 effectively banned a long list of chlorofluorocarbons (CFCs) traditionally used in air conditioning and refrigeration applications. The refrigeration and air conditioning industries have responded by developing and testing new, alternative refrigerants that are less damaging to the atmosphere upon release. Despite a reputation for quality and reliability, air conditioning systems do occasionally fail. One of the more common failure modes in a hermetic system is a motor burnout. Motor burnouts can occur by various mechanisms. One of the most common scenarios is a locked motor rotor, which may result from a damaged bearing. The resulting electrical motor burnout is caused by overheating of the locked rotor and subsequent failure of the insulation. This is primarily a thermal breakdown process

Magnetic field topology during July 14–16 2000 (Bastille Day) solar CME event

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95295/1/grl15382.pd

A System for Measuring Defect Induced Beam Modulation on Inertial Confinement Fusion-class Laser Optics

A multi-wavelength laser based system has been constructed to measure defect induced beam modulation (diffraction) from ICF class laser optics. The Nd:YLF-based modulation measurement system (MMS) uses simple beam collimation and imaging to capture diffraction patterns from optical defects onto an 8-bit digital camera at 1053, 527 and 351 nm. The imaging system has a field of view of 4.5 x 2.8 mm{sup 2} and is capable of imaging any plane from 0 to 30 cm downstream from the defect. The system is calibrated using a 477 micron chromium dot on glass for which the downstream diffraction patterns were calculated numerically. Under nominal conditions the system can measure maximum peak modulations of approximately 7:1. An image division algorithm is used to calculate the peak modulation from the diffracted and empty field images after the baseline residual light background is subtracted from both. The peak modulation can then be plotted versus downstream position. The system includes a stage capable of holding optics up to 50 pounds with x and y translation of 40 cm and has been used to measure beam modulation due to solgel coating defects, surface digs on KDP crystals, lenslets in bulk fused silica and laser damage sites mitigated with CO{sub 2} lasers

Sensing remote nuclear spins

Sensing single nuclear spins is a central challenge in magnetic resonance based imaging techniques. Although different methods and especially diamond defect based sensing and imaging techniques in principle have shown sufficient sensitivity, signals from single nuclear spins are usually too weak to be distinguished from background noise. Here, we present the detection and identification of remote single C-13 nuclear spins embedded in nuclear spin baths surrounding a single electron spins of a nitrogen-vacancy centre in diamond. With dynamical decoupling control of the centre electron spin, the weak magnetic field ~10 nT from a single nuclear spin located ~3 nm from the centre with hyperfine coupling as weak as ~500 Hz is amplified and detected. The quantum nature of the coupling is confirmed and precise position and the vector components of the nuclear field are determined. Given the distance over which nuclear magnetic fields can be detected the technique marks a firm step towards imaging, detecting and controlling nuclear spin species external to the diamond sensor

The negatively charged nitrogen-vacancy centre in diamond: the electronic solution

The negatively charged nitrogen-vacancy centre is a unique defect in diamond that possesses properties highly suited to many applications, including quantum information processing, quantum metrology, and biolabelling. Although the unique properties of the centre have been extensively documented and utilised, a detailed understanding of the physics of the centre has not yet been achieved. Indeed there persists a number of points of contention regarding the electronic structure of the centre, such as the ordering of the dark intermediate singlet states. Without a sound model of the centre's electronic structure, the understanding of the system's unique dynamical properties can not effectively progress. In this work, the molecular model of the defect centre is fully developed to provide a self consistent model of the complete electronic structure of the centre. The application of the model to describe the effects of electric, magnetic and strain interactions, as well as the variation of the centre's fine structure with temperature, provides an invaluable tool to those studying the centre and a means to design future empirical and ab initio studies of this important defect.Comment: 24 pages, 6 figures, 10 table

Ionospheric Storm Simulations Driven by Magnetospheric MHD and Empirical Models with Data Comparisons

The results of two ionospheric simulations are compared with each other and with ionospheric observations of the southern hemisphere for the magnetic cloud passage event of January 14, 1988. For most of the event one simulation agrees with observations, while the other does not. Electric fields and electron precipitation patterns generated by a magnetospheric MHD model are used as inputs to a physical model of the ionosphere in the successful simulation, while empirical electric fields and electron precipitation are used as the inputs for the second simulation. In spite of ionospheric summer conditions a large and deep polar hole is developed. This is seen in the in situ plasma observations made by the DMSP-F8 satellite. The hole is surprisingly present during both northward and southward IMF conditions. It is deepest for the storm phase of the southward IMF period. A well-defined tongue of ionization is formed during this period. These features have been reproduced by the TDIM-MHD simulation and to a lesser extent by the TDIM-empirical simulation. However, the model simulations have not been able to generate a storm enhanced density where one was observed by DMSP-F8 during the initial phase of the storm. The differences between the two F region ionospheric simulations are attributed to differences in the magnetospheric electric fields and precipitation patterns used as inputs. This study provides a unique first simulation of the ionosphere\u27s response to self-consistent electric field and auroral precipitation patterns over a 24-hour period that leads into a major geomagnetic storm

Cavities of weak magnetic field strength in the wake of FTEs: Results from global magnetospheric MHD simulations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94797/1/grl25783.pd