A5088201943- Atomic and Subatomic Physics Research
- Muon and positron interactions and applications
- Advanced NMR Techniques and Applications
- Rare-earth and actinide compounds
- Advancements in Battery Materials
- Quantum optics and atomic interactions
- Magnetic and transport properties of perovskites and related materials
- Physics of Superconductivity and Magnetism
- Quantum, superfluid, helium dynamics
- Advanced Condensed Matter Physics
- Graphene research and applications
- Magnetic properties of thin films
- Advanced MRI Techniques and Applications
- Advanced Frequency and Time Standards
- Cold Atom Physics and Bose-Einstein Condensates
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Iron-based superconductors research
- Magnetic Properties of Alloys
- Superconductivity in MgB2 and Alloys
- Blind Source Separation Techniques
- Dark Matter and Cosmic Phenomena
- Semiconductor materials and interfaces
- Fusion materials and technologies
- Quantum and electron transport phenomena
National Institute of Standards and Technology
2023-2024
National Institute of Standards
2024
University of Colorado Boulder
2022
Physikalisch-Technische Bundesanstalt
2014-2021
University of Alberta
2006-2015
National Tsing Hua University
2011-2015
TRIUMF
2011
University of British Columbia
2011
Rutherford Appleton Laboratory
2008
University of Oxford
2008
A versatile and portable magnetically shielded room with a field of (700 ± 200) pT within central volume 1 m × gradient less than 300 pT/m, achieved without any external stabilization or compensation, is described. This performance represents more hundredfold improvement the state art for two-layer magnetic shield provides an environment suitable next generation precision experiments in fundamental physics at low energies; particular, searches electric dipole moments systems tests...
We report results of a new technique to measure the electric dipole moment $^{129}\mathrm{Xe}$ with $^{3}\mathrm{He}$ comagnetometry. Both species are polarized using spin-exchange optical pumping, transferred measurement cell, and transported into magnetically shielded room, where SQUID magnetometers detect free precession in applied magnetic fields. The result from one week campaign 2017 2.5 2018, combined detailed study systematic effects, is...
We present a realization of magnetic sensor based on electromagnetically induced transparency (EIT) resonances observed in hot Rb vapor using lin∥lin polarized dichromatic light and evaluate scalar vector capabilities the for measuring Earth-like fields. demonstrate measurement sensitivity 2
The effects of the grain-boundary-induced lattice disorder on resistivity, magnetization, and specific heat a prototypical manganite Sm0.55Sr0.45MnO3 near half doping were investigated at temperatures metal-insulator transition. An increasing softens magnetic phase transition from first order into second Furthermore, peaks in resistivity are broaden there is an increase charge-carrier scattering rates metallic insulating states. origin these phenomena discussed.
We investigated magnetotransport properties, such as the clustering temperature ${T}^{\ensuremath{\ast}}$, ${T}_{C}$, magnetoresistance, and resistivity of ${\text{Sm}}_{0.55}{\text{Sr}}_{0.45}{\text{MnO}}_{3}$ manganite (which exhibits a non-Curie-Weiss (CW) behavior, resulting from multiphase competition coexistence), their evolution due to ruthenium doping on Mn-ion site ($B$-site). These results have been compared with predictions model system two competing states in presence quenched...
Depth-controlled $\ensuremath{\beta}$-NMR was used to study highly spin-polarized $^{8}\mathrm{Li}^{+}$ in a Cu film of thickness $100\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ deposited onto MgO substrate. The positive Knight shifts and spin relaxation data show that occupies two sites at low temperatures, assigned be the substitutional $(S)$ octahedral $(O)$ interstitial sites. Between 50 $150\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, there is site change from $O$ $S$. temperature dependence...
Abstract Vector atomic magnetometers that incorporate electromagnetically induced transparency (EIT) allow for precision measurements of magnetic fields are sensitive to the directionality observed field by virtue fundamental physics. However, a practical methodology accurately recovering longitudinal angle local through observations EIT spectra has not been established. In this work, we address problem determination with an unsupervised machine learning algorithm utilizing nonlinear...
Magnetic phase transition in the manganite films has been found to be induced by structural of ${\text{SrTiO}}_{3}$ substrate at ${T}_{s}=105\text{ }\text{K}$ [Vlasko-Vlasov et al., Phys. Rev. Lett. 84, 2239 (2000) and Ziese New J. 10, 063024 (2008)]. However, no change electrical transport properties detected this temperature. Here we report observation satellite peaks temperature dependence coefficient resistivity (TCR) temperatures around 105 K ultrathin grown on substrates, triggered...
We studied the influence of optical excitation on three muonium centers ${\mathrm{Mu}}_{T}^{0}$, ${\mathrm{Mu}}_{\mathit{BC}}^{0}$, and ${\mathrm{Mu}}_{\mathit{BC}}^{+}$ in high resistivity silicon. These investigations were carried out spin precession signature each center as a function temperature. It is found that photoexcitation resulted significant enhancements depolarization rates signals underwent interactions with photogenerated free carriers. The results are described by three-state...
By using photoexcitation, we unambiguously establish that the well-known diamagnetic muonium spin precession signal in Ge is fact due to two states. Their temperature dependences are studied up room temperature. The one of these states strongly influenced by photoexcited carriers while other not. identification centers discussed.
The magnetic properties of a 180-nm-thick epitaxial film the dilute semiconductor Ga${}_{1\ensuremath{-}x}$Mn${}_{x}$As with $x=0.054$ are investigated using beta-detected NMR low-energy implanted ${}^{8}$Li${}^{+}$. There is broad distribution local fields in layer, reflecting inhomogeneity system. resonance (representing field distribution) followed as function temperature through ferromagnetic transition. average hyperfine at ${}^{8}$Li nucleus measured to be positive and on order 150 G...
The absolute frequency measurement of thallium $6{P}_{1/2}\ensuremath{\rightarrow}7{S}_{1/2}$ transitions using a self-referencing optical comb is reported. Our results can be used as benchmark for the accurate wave-function calculations heavy atoms, and then improve atomic parity-nonconservation amplitude. centers have been precisely determined by Doppler-free saturation spectroscopy utilizing pair counterpropagating laser beams intersecting with beam. We achieved determination transition...
One of the most precisely determined upper limits for electron electric dipole moment (EDM) is set by thallium (Tl) atomic beam experiment. way to enhance sensitivity setup laser cool Tl atoms reduce EDM-like phase caused E$\ifmmode\times\else\texttimes\fi{}$v effect. In this report, a cooling scheme based on $6{P}_{3/2}(F=2)\ensuremath{\leftrightarrow}6{D}_{5/2}({F}^{\ensuremath{'}}=3)$ transition in proposed. The absolute frequency measurement nearly closed-cycle was performed an...
We report a refined determination of muonium 1$S$-2$S$ transition frequency and its isotope shift with deuterium by recalibrating the iodine reference lines using an optical comb. The for transitions are determined precision $2.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$ $1.7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$, respectively. An updated muonium-deuterium isotope-shift is derived from these references to be 11 203 464.9(9.2)(4.0) MHz, in agreement...
We present $\ensuremath{\beta}$-detected NMR measurements of the spin-lattice relaxation $^{8}\mathrm{Li}^{+}$ implanted into an epitaxial heterostructure based on a 100 nm thick film ferromagnetic (FM) EuO as function temperature through its FM transition. In state, rate follows same dependence, determined by magnon scattering mechanisms, observed in bulk $^{153}\mathrm{Eu}$ NMR, but above 40 K, signal is wiped out. also find that stopped material adjacent to magnetic layer exhibits spin...
The detailed dynamics of the positively charged muonium (Mu+) in heavily doped p-type Si:B is reported. Below 200 K, Mu+ static and isolated, located a stretched Si-Si bond. Above approximately diffuses incoherently. At temperatures higher than 300 Mu+-B- complex formed while above 520 it starts to dissociate. There significant enhancement diffusion Si compared H+ D+-this attributed its smaller mass.
We report {\beta} detected nuclear magnetic resonance ({\beta}NMR) measurements of 8Li+ implanted into high purity Pt. The frequency the 8Li {\beta}NMR and spin-lattice relaxation rates 1/T1 were measured at temperatures ranging from 3 to 300 K. Remarkably, both rate Knight shift K depend linearly on temperature T although bulk susceptibility does not. is found scale with Curie-Weiss dependence Pt extrapolated low temperatures. This attributed a defect response enhanced paramagnetism Pt,...
The noise and stability of a current source are limited by the quality components used for construction, such as voltage reference chips, resistors, power supplies. A state-of-the-art commercial typically exhibits no better than parts in 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> . In this paper, we present way to implement with "external" electrical references. This approach allows be decoupled from characteristics main supply...
The radio frequency telecommunication at a kilohertz range through an electrically conductive medium is often impeded by the strong reflection and absorption interface. polarization helicity of magnetic field can be modulated/demodulated to provide new communication protocol potentiality circumvent these issues. Here, miniature quantum receiver, capable simultaneously discriminating two possible helicities field, presented. core physics package constitutes optically pumped atomic...
Level-crossing resonances are observed for spin-polarized ${}^{8}$Li in copper at 200 K. The positions of the as a function magnetic field and crystal orientation precise measure induced quadrupolar interaction on nearest-neighbor Cu spins provide unambiguous evidence that occupies substitutional site. detected enhancements spin relaxation rate much broader than predicted from static Hamiltonian. A strong collision model is used to extract decoherence time result dipolar coupling...
A co-located 3He and 129Xe nuclear spin free precession measurement at sub-μT magnetic field was carried out in a magnetically shielded environment. The uncorrected quotient of the gyromagnetic ratios between neutral atoms is determined to be 2.754 082 81(07), accounting for only statistical error. Our shows that this ratio has stability 1.4×10-5/ √τ, demonstrating ability reach current precision limit 10000 s averaging time τ. This enough next-generation EDM search based on similar...
<p>An unsupervised machine learning algorithm utilizing nonlinear dimensionality reduction has been developed to interface with spectroscopic measurements from an atomic rubidium optical magnetometer. The magnetometer uses Electromagnetically Induced Transparency (EIT) spectroscopy vapor cells in order observe magneto-sensitive spin transitions of the 87Rb atom. Rb EIT result observation seven transmission peaks associated available two-photon resonances between D1 line Zeeman...