A5066311294- Cold Atom Physics and Bose-Einstein Condensates
- Quantum, superfluid, helium dynamics
- Quantum optics and atomic interactions
- Quantum Information and Cryptography
- Quantum Mechanics and Applications
- Radio Wave Propagation Studies
- Neutrino Physics Research
- Advanced Data Storage Technologies
- Advanced Chemical Physics Studies
- Atomic and Subatomic Physics Research
- Magnetic confinement fusion research
- Laser-Matter Interactions and Applications
- Astrophysics and Cosmic Phenomena
- Advanced Frequency and Time Standards
- Distributed and Parallel Computing Systems
- Particle physics theoretical and experimental studies
- Spectroscopy and Laser Applications
- Particle accelerators and beam dynamics
- Mass Spectrometry Techniques and Applications
- Spectroscopy and Quantum Chemical Studies
- Ion-surface interactions and analysis
- Atomic and Molecular Physics
- Quantum many-body systems
- Dark Matter and Cosmic Phenomena
- Precipitation Measurement and Analysis
University of Wisconsin System
2024
Ursinus College
2009-2024
University of Wisconsin–Madison
2024
Princeton Plasma Physics Laboratory
2002-2021
Bryn Mawr College
2004-2007
Swarthmore College
2007
Massachusetts Institute of Technology
1952-2005
Princeton University
2002-2003
Bendix Field Engineering Corporation (United States)
1962-1965
MIT Lincoln Laboratory
1955
The general theory of the Faraday effect associated with a single molecular absorption line is presented. perturbation transition probabilities by field in producing asymmetrical rotation discussed, and calculated for alkali band systems ${\mathrm{I}}_{2}$. observations on ${\mathrm{I}}_{2}$ agree predictions. longitudinal Zeeman patterns changes these produced are related to vector model use criterion that transitions which involve little change direction $J$, rotational axis, most probable...
The first results of edge-localized mode (ELM) pacing using small spherical lithium granules injected mechanically into H-mode discharges are reported. Triggering ELMs was accomplished a simple rotating impeller to inject sub-millimetre size at speeds few tens meters per second the outer midplane EAST fusion device. During injection phase, were triggered with near 100% efficiency and amplitude induced as measured by Dα clearly reduced compared contemporaneous naturally occurring ELMs. In...
Atoms in an ultracold highly excited sample are strongly coupled through the dipole-dipole interaction. In effort to understand and manipulate complicated interactions this system we investigating their dependence on relative orientation of dipoles. By focusing a 480 nm beam from tunable dye laser into magneto-optical trap, produce nearly one-dimensional Rydberg atoms. The trap lies at center four conducting rods with which can vary magnitude direction electric field thus controlling dipoles...
Experiments of the past decade give stronger fields well beyond horizon than are calculated by 4/3 airless earth approximation. Post-war work on theory WKB approximation for wave propagation in slowly varying inhomogeneous media, and peculiar results eigenvalues bilinear refractive index proffle offer valuable clues search an oversight conventional theory. If absolute value as gradient at earth's surface be specified, with a profile which tapers to vacuum some arbitrarily large height, then...
Ultracold highly excited atoms in a magneto-optical trap (MOT) are strongly coupled by the dipole-dipole interaction. We have investigated importance of many-body effects controlling dimensionality and density sample. three different cylindrical volumes MOT to Rydberg states. At small radius, where sample is nearly one-dimensional, interactions suppressed. larger radii, becomes three-dimensional apparent.
Ultracold Rydberg atoms in a static electric field can exchange energy via the dipole-dipole interaction. The Stark effect shifts levels of which tunes into resonance at specific values (F\"orster resonances). We excite rubidium to states by focusing either 480 nm beam from tunable dye laser or pair diode lasers magneto-optical trap. trap lies center configuration electrodes. scan controlling voltage on electrodes while measuring fraction that interact. Dipole-dipole interaction spectra are...
Results are presented of twilight-region propagation experiments on 128 Mc over the airline route from San Francisco, Calif., to Honolulu, Hawaii, including high-altitude jet flights. Greatly enhanced fields observed most flights, and these correlated with a new meteorological parameter related mean index gradient atmospheric stability. It is also shown that minimum conditions some 20 db improved other ground-to-ground or ground-to-air experiments. This improvement attributed greater antenna...
We excite ultracold rubidium atoms in a magneto-optical trap to coherent superposition of the three $|{m}_{j}|$ sublevels $37{d}_{5/2}$ Rydberg state. After some delay, during which relative phases components can evolve, we apply an electric field pulse ionize electron and send it detector. The traverses many avoided crossings Stark levels as ionizes. net effect transitions at these is mix amplitudes initial into same final states ionization. Similar Mach-Zehnder interferometer, have...
Quantum control of the pathway along which a Rydberg electron field ionizes is experimentally and computationally demonstrated. Selective ionization typically done with slowly rising electric pulse. The ${(1/{n}^{*})}^{4}$ scaling classical threshold leads to rough mapping between arrival time signal principal quantum number electron. This complicated by many avoided level crossings that must traverse on way ionization, in general broadening time-resolved signal. In order pathway, thus...
The long-range, anisotropic nature of the interaction among atoms in an ultracold dipolar gas leads to a rich array possibilities for studying many-body physics. In this work, highly excited is used study energy transport due long-range dipole-dipole interaction. A technique developed measure both internal states interacting Rydberg and their positions space. This demonstrated by observing exchange between two spatially separated groups different states. Simulations confirm general features...
A simple estimate of the feeble internal reflection from normal troposphere explains remarkably well long puzzling fields beyond horizon throughout VHF and microwave spectrum. Even in absence ducts, continuous decrease with height index refraction under gravitational influence makes an inhomogeneous continuously stratified medium. The effective earth's radius notion allows for refractive effect this inhomogeneity calculating diffracted field horizon, but not reflections. bilinear model...
The global nature of the ITER project along with its projected approximately petabyte-per-day data generation presents not only a unique challenge but also an opportunity for fusion community to rethink, optimize, and enhance our scientific discovery process. Recognizing this, collaborative research computational scientists was undertaken over past several years create framework large-scale movement across wide-area networks enable near-real-time analysis data. This would broaden available...
The dipole-dipole interaction among ultra-cold Rydberg atoms is simulated. We examine a general scheme in which two excited to the x and x' states are converted y y' via Forster resonance. arranged spatially separated groups, each consisting of only one species atom. record fraction state as distance between groups varied. With zero detuning many-body effect that relies on always resonant interactions causes have finite range. When greater than zero, another peak when some away from other....
The electron signals from the field ionization of two closely spaced Rydberg states rubidium-85 are separated using quantum control. In selective ionization, state distribution a collection atoms is measured by ionizing with ramped electric field. Generally, in higher energy ionize at lower fields, so ionized electrons which detected earlier time can be correlated states. However, resolution this technique limited Stark effect. As increased, encounters numerous avoided level crossings split...
Rubidium Rydberg atoms in either |m_{j}| sublevel of the 36p_{3/2} state can exchange energy via Stark-tuned Förster resonances, including two-, three-, and four-body dipole-dipole interactions. Three-body interactions this type were first reported categorized by Faoro et al. [Nat. Commun. 6, 8173 (2015)NCAOBW2041-172310.1038/ncomms9173] their Borromean nature was confirmed Tretyakov [Phys. Rev. Lett. 119, 173402 (2017)PRLTAO0031-900710.1103/PhysRevLett.119.173402]. We report time dependence...
The dipole-dipole interaction between two Rydberg atoms depends on the relative orientation of and change in magnetic quantum number. We simulate effect this anisotropy energy transport an amorphous many atom system subject to a homogeneous applied electric field. consider experimentally feasible geometries find that effects should be measurable current generation imaging experiments. In both $p$ character are localized small region space which is immersed larger filled with $s$ character....
Since the last year of World War II, outstanding problem in tropospheric propagation research has been explanation high observed field, strengths well beyond horizons high-power transmitters, at all frequencies throughout vhf and microwave spectrum, widely separated parts world under vastly different conditions climate terrain' The disagreement between measurements calculations based on conventional theory over a smooth earth surmounted by an atmosphere with standard refraction (4/3 earth)...
Following the decommissioning of Main Injector Neutrino Oscillation Search (MINOS) experiment, muon and hadron monitors have emerged as vital diagnostic tools for NuMI Off-axis νμ Appearance (NOvA) experiment at Fermilab. These are crucial overseeing Neutrinos (NuMI) beam. This study endeavors to ensure monitor signal quality correlate them with beam profile. Leveraging simulations, we systematically explore responses variations in proton-beam lattice parameters. Through amalgamation...
We simulate the dynamics of Rydberg atoms resonantly exchanging energy via two-, three-, and four-body dipole-dipole interactions in a one-dimensional array. Using simplified models realistic experimental system, we study initial-state survival probability, mean level spacing, spread entanglement, properties eigenstates. By exploring range disorders interaction strengths, find regions parameter space where three- either fail to thermalize or do so slowly. The interplay between stronger...
A static electric field of a few V/cm shifts the energy levels ultracold Rydberg atoms in magneto-optical trap. For given principle quantum number, most are nearly degenerate at zero and fan out with increasing to form manifold. We excite near center manifold, where spacing is harmonic, allow them exchange via resonant dipole-dipole interactions. measure time evolution as spreads away from which reveals that system fails thermalize for long interaction times. computational model includes...
In 1965 there was a strong reawakening of interest in “angel” or clear‐air radar echoes. Atlas [1965] postulated that "dot" point‐like angles were reflections from smooth, sharp boundaries at the apex convective thermals. Focusing curved surface reduced requirement on index gradient to 1 N unit through em; however, smoothness fraction em over first Fresnel zone is still severe and lacks experimental confirmation. Dot angel activity night requires another explanation. Hardy, Atlas, Glover...