0000000001043774
AUTHOR
D. Budker
Optically Detected Magnetic Resonances of Nitrogen-Vacancy Ensembles in 13C Enriched Diamond
We present an experimental and theoretical study of the optically detected magnetic resonance signals for ensembles of negatively charged nitrogen-vacancy (NV) centers in 13C isotopically enriched single-crystal diamond. We observe four broad transition peaks with superimposed sharp features at zero magnetic field and study their dependence on applied magnetic field. A theoretical model that reproduces all qualitative features of these spectra is developed. Understanding the magnetic-resonance spectra of NV centers in isotopically enriched diamond is important for emerging applications in nuclear magnetic resonance.
Search for Dark-Matter-Induced Oscillations of Fundamental Constants Using Molecular Spectroscopy
Physical review letters 129(3), 031302 (2022). doi:10.1103/PhysRevLett.129.031302
Isotopic variation of parity violation in atomic ytterbium: method of measurements and analysis of systematic effects
We present a detailed description of experimental studies of the parity violation effect in an isotopic chain of atomic ytterbium (Yb), whose results were reported in a recent Letter [Antypas et al., Nat. Phys. 15, 120 (2019)]. We discuss the principle of these measurements, made on the Yb 6s$^2$ $^1$S$_0 \rightarrow $5d6s $^3$D$_1$ optical transition at 408 nm, describe the experimental apparatus, and give a detailed account of our studies of systematic effects in the experiment. Our results offer the first direct observation of the isotopic variation in the atomic parity violation effect, a variation which is in agreement with the prediction of the Standard Model. These measurements are u…
A network of magnetometers for multi-scale urban science and informatics
The magnetic signature of an urban environment is investigated using a geographically distributed network of fluxgate magnetometers deployed in and around Berkeley, California. The system hardware and software are described and initial operations of the network are reported. The sensors measure vector magnetic fields at a 3960 Hz sample rate and are sensitive to 0.1 nT/Hz. Data from individual stations are synchronized to ±120 µs using global positioning system (GPS) and computer system clocks and automatically uploaded to a central server. We present the initial observations of the network and preliminary efforts to correlate sensors. A wavelet analysis is used to stud…
Network of sensitive magnetometers for urban studies
The magnetic signature of an urban environment is investigated using a geographically distributed network of fluxgate magnetometers deployed in and around Berkeley, California. The system hardware and software are described and results from initial operation of the network are reported. The sensors sample the vector magnetic field with a 4 kHz resolution and are sensitive to fluctuations below 0.1 $\textrm{nT}/\sqrt{\textrm{Hz}}$. Data from separate stations are synchronized to around $\pm100$ $\mu{s}$ using GPS and computer system clocks. Data from all sensors are automatically uploaded to a central server. Anomalous events, such as lightning strikes, have been observed. A wavelet analysis…
Overview of the Cosmic Axion Spin Precession Experiment (CASPEr)
An overview of our experimental program to search for axion and axion-like-particle (ALP) dark matter using nuclear magnetic resonance (NMR) techniques is presented. An oscillating axion field can exert a time-varying torque on nuclear spins either directly or via generation of an oscillating nuclear electric dipole moment (EDM). Magnetic resonance techniques can be used to detect such an effect. The first-stage experiments explore many decades of ALP parameter space beyond the current astrophysical and laboratory bounds. It is anticipated that future versions of the experiments will be sensitive to the axions associated with quantum chromodynamics (QCD) having masses $\lesssim 10^{-9}~{\rm…