A5012072957- Atomic and Subatomic Physics Research
- NMR spectroscopy and applications
- Advanced MRI Techniques and Applications
- Quantum optics and atomic interactions
- Advanced NMR Techniques and Applications
- Diamond and Carbon-based Materials Research
- Cold Atom Physics and Bose-Einstein Condensates
- Hydrocarbon exploration and reservoir analysis
- Quantum, superfluid, helium dynamics
- High-pressure geophysics and materials
- Hydraulic Fracturing and Reservoir Analysis
- Magnetic Field Sensors Techniques
- Magnetic and transport properties of perovskites and related materials
- Force Microscopy Techniques and Applications
- Solid-state spectroscopy and crystallography
- Advanced Fiber Laser Technologies
- Water Quality Monitoring Technologies
- Magnetism in coordination complexes
- Mechanical and Optical Resonators
- Geophysical and Geoelectrical Methods
- Neutrino Physics Research
- Characterization and Applications of Magnetic Nanoparticles
- Advanced Thermodynamic Systems and Engines
- Mineral Processing and Grinding
- Semiconductor materials and devices
Chevron (China)
2021
Chevron (United States)
2016-2020
Lawrence Berkeley National Laboratory
2010-2017
University of California, Berkeley
2010-2014
QB3
2012-2014
University of California System
2013
Princeton University
2004-2009
We describe a vector alkali–metal magnetometer that simultaneously and independently measures all three components of the magnetic field. Using feedback system, total field at location is kept near zero, suppressing broadening due to spin-exchange collisions. The resonance linewidth signal strength compare favorably with two different scalar operation modes in which relaxation only partially suppressed. Magnetic sensitivity on order 1pT∕Hz demonstrated laboratory environment without shields.
We describe an alkali-metal magnetometer for detection of weak magnetic fields in the radio-frequency (rf) range. High sensitivity is achieved by tuning Zeeman resonance alkali atoms to rf frequency and partially suppressing spin-exchange collisions vapor. demonstrate field $2\text{ }\text{ }\mathrm{fT}/{\mathrm{Hz}}^{1/2}$ at a 99 kHz with width 400 Hz. also derive simple analytic expression fundamental limit on show that about $0.01\text{ can be practical system measurement volume...
A radio-frequency tunable atomic magnetometer is developed for detection of nuclear quadrupole resonance (NQR) from room temperature solids. It has a field sensitivity 0.24fT∕Hz1∕2 at the 423kHz N14 NQR frequency ammonium nitrate. potential application nitrogen-containing explosives which difficult with conventional tuned copper coils due to poor signal-to-noise ratio (SNR) below few megahertz. The signal 22g powdered nitrate located 2cm away sensor detected SNR 9 in 4.4-s-long multiple echo...
Antirelaxation surface coatings allow long spin relaxation times in alkali-metal cells without buffer gas, enabling faster diffusion of the alkali atoms throughout cell and giving larger signals due to narrower optical linewidths. Effective were previously unavailable for operation at temperatures above 80 °C. We demonstrate that octadecyltrichlorosilane (OTS) can potassium or rubidium experience hundreds collisions with before depolarizing, an OTS coating remains effective up about 170 °C...
We observe quantum beats with periodic revivals due to non-linear spacing of Zeeman levels in the ground state potassium atoms and demonstrate their synchronous optical pumping by double modulation light at Larmor frequency revival frequency. show that increases degree spin polarization a factor 4. As practical example, we explore application this double-modulation technique atomic magnetometers operating geomagnetic field range find it can increase sensitivity reduce magnetic...
Many technologies based on cells containing alkali-metal atomic vapor benefit from the use of antirelaxation surface coatings in order to preserve spin polarization. In particular, paraffin has been used for this purpose several decades and demonstrated allow an atom experience up 10 000 collisions with walls its container without depolarizing, but details operation remain poorly understood. We apply modern bulk techniques study characterize properties that enable effective preservation...
The evaluation of different surface coatings used in alkali metal atomic magnetometers is necessary for the improvement sensitivity these devices. A method to measure polarization lifetime atoms region between substrates with was developed determine effectiveness coating at preserving spin as well chemical compatibility and high-temperature stability. Multiple can be compared under identical experimental conditions, using an geometry that allows characterization before after lifetime....
We operate a nitrogen vacancy (NV-) diamond magnetometer at ambient temperatures and study the dependence of its bandwidth on experimental parameters including optical microwave excitation powers. introduce an analytical theory that yields explicit formula for response ensemble NV- spins to oscillating magnetic field, such as in NMR applications. measure detection 1.6 MHz sensitivity 4.6 nT/Hz^(1/2), unprecedented detector with this active volume close photon shot noise limit our experiment.
We demonstrate that the spin decoherence of nitrogen vacancy (NV) centers in diamond can be suppressed by a transverse magnetic field if electron bath is primary source. The NV coherence, created ``a decoherence-free subspace,'' protected component zero-field splitting, increasing spin-coherence time about twofold. due to also at fields stronger than \ensuremath{\sim}25 G when applied parallel symmetry axis. Our method used extend similar systems for applications quantum computing, sensing,...
We report sensitive detection of the nuclear quadrupolar interaction 14N spin nitrogen-vacancy (NV) center using electron echo envelope modulation technique. applied a weak transverse magnetic field to system so that certain forbidden transitions became weakly allowed due second-order effects involving nonsecular terms hyperfine interaction. The cause spin-echo signal, and theoretical analysis suggests frequency is primarily determined by frequency; numerical simulations confirm analytical...
Abstract Low thermal-equilibrium nuclear spin polarizations and the need for sophisticated instrumentation render conventional magnetic resonance (NMR) spectroscopy imaging (MRI) incompatible with small-scale microfluidic devices. Hyperpolarized 129 Xe gas has found use in study of many materials but required very large expensive instrumentation. Recently a microfabricated device modest demonstrated all-optical hyperpolarization detection gas. This was limited by less than 1%, NMR signals...
Nuclear magnetic resonance (NMR) relaxometry and diffusometry are important tools for the characterization of heterogeneous materials porous media, with applications including medical imaging, food oil-well logging. These methods can be extremely effective in where high-resolution NMR is either unnecessary, impractical, or both, as case emerging field portable chemical characterization. Here, we present a proof-of-concept experiment demonstrating use high-sensitivity optical magnetometers...
The light-induced desorption of Rb atoms from a paraffin coating is studied with depth-profiling X-ray photoelectron spectroscopy (XPS) using tunable synchrotron radiation. Following exposure, shifts the C1s signal to higher binding energies, as well appearance lower energy components in O1s region, were observed. These effects diminished after irradiation desorbing light. Additionally, following desorbing-light irradiation, changes depth-dependent concentration carbon observations offer an...
Abstract Nuclear magnetic resonance (NMR) relaxometry and diffusometry are important tools for the characterization of heterogeneous materials porous media, with applications including medical imaging, food oil‐well logging. These methods can be extremely effective in where high‐resolution NMR is either unnecessary, impractical, or both, as case emerging field portable chemical characterization. Here, we present a proof‐of‐concept experiment demonstrating use high‐sensitivity optical...
Abstract Dielectric measurements of reservoir rocks are used to estimate important petro‐physical properties such as water‐filled porosity and pore surface textures. However, complex dielectric polarization processes that occur in strongly dependent on frequency, making physically meaningful interpretation broadband data difficult. At high frequency (> 10 MHz) permittivity primarily relates the volume fractions constituents (i.e., saturation, minerals), while at lower (< MHz), is...
Abstract Unlike conventional gas reservoirs, shale reservoirs contain organic mesopores that have pore sizes ranging from 2 to 50 nm. These pores may cause capillary condensation of confined hydrocarbons due the non-negligible pressure. A novel phase equilibrium model has been developed quantify effects size distribution on behavior hydrocarbons, including occurrence condensation. However, it remains a challenge assess by laboratory experiments. This is because pressure-volume-temperature...
Dynamic nuclear polarisation, which transfers the spin polarisation of electrons to nuclei, is routinely applied enhance sensitivity magnetic resonance; it also critical in spintronics, particularly when hyperpolarisation can be produced and controlled optically or electrically. Here we show complete nuclei located near optically-polarised nitrogen-vacancy (NV) centre diamond. When approaching ground-state level anti-crossing condition NV electron spins, 13C first-shell are polarised a...