A5048102935- Quantum optics and atomic interactions
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum Information and Cryptography
- Atomic and Subatomic Physics Research
- Behavioral and Psychological Studies
- Child and Adolescent Psychosocial and Emotional Development
- Laser-Matter Interactions and Applications
- Autism Spectrum Disorder Research
- Venous Thromboembolism Diagnosis and Management
- Islamic Studies and History
- Politics and Conflicts in Afghanistan, Pakistan, and Middle East
- Quantum, superfluid, helium dynamics
- Quantum Mechanics and Applications
- Advanced Frequency and Time Standards
- Emergency and Acute Care Studies
- Sepsis Diagnosis and Treatment
- Photonic and Optical Devices
- Respiratory Support and Mechanisms
- Cardiac Arrest and Resuscitation
- Spectroscopy and Quantum Chemical Studies
- Mechanical and Optical Resonators
- Advanced Fiber Laser Technologies
- Spectroscopy and Laser Applications
- Atomic and Molecular Physics
- Trauma and Emergency Care Studies
University of Maryland, Baltimore
1996-2025
Pennsylvania State University
2025
Prisma Health
2025
Williams College
2014-2024
University of South Florida
2023
University of Maryland Medical Center
2016-2022
Royal Victoria Hospital
2021
University of Ulster
2021
University College London
1986-2018
Great Ormond Street Hospital
2018
Photoassociation is the process in which two colliding atoms absorb a photon to form an excited molecule. The development of laser-cooling techniques for producing gases at ultracold $(<1\phantom{\rule{0.3em}{0ex}}\mathrm{mK})$ temperatures allows photoassociation spectroscopy be performed with very high spectral resolution. Of particular interest investigation molecular states whose properties can related, precision, their constituent ``complications'' chemical binding accounted by few...
There have been several proposals to the effect that special service decisions could be based, at least in part, on construct of response intervention and not necessarily traditional child measures. Single-case designs focus intensity are reviewed as a potential evaluation framework for interdisciplinary teams help answer services resource questions. Increasing-intensity based sequential trials ordered continuum builds intensity. Decreasing-intensity start with more comprehensive or...
We have observed optically induced Feshbach resonances in a cold ( <1 mK) sodium vapor. The optical coupling of the ground and excited-state potentials changes scattering properties an ultracold gas much same way as recently magnetically resonances, but allows for some experimental conveniences associated with using lasers. can be varied by changing either intensity or detuning laser tuned near photoassociation transition to molecular state dimer. In principle this method length any atomic...
We report a preliminary value for the zero magnetic field Na 2S(f = 1, m - 1) + scattering length, a1,-1. This parameter describes low-energy elastic two-body processes in dilute gas of composite bosons and determines, to large extent, macroscopic wavefunction Bose condensate trap. Our length is obtained from photoassociative spectroscopy with samples uncondensed atoms. The temperature atoms sufficiently low that contributions three lowest partial waves dominate spectrum. observed lineshapes...
An SU(1,1) interferometer replaces the beamsplitters in a Mach-Zehnder with nonlinear interactions and offers potential of achieving high phase sensitivity applications low optical powers. We present novel variation which second interaction is replaced balanced homodyne detection. The phase-sensing quantum state two-mode squeezed produced by seeded four-wave-mixing Rb vapor. Measurements as function operating point show that even $\approx35~\%$ loss this device can surpass standard limit 4~dB.
We form ultracold Na2 molecules by single-photon photoassociation of a Bose-Einstein condensate, measuring the rate, linewidth, and light shift J = 1, v 135 vibrational level A1 Sigma (+)(u) molecular state. The rate constant increases linearly with intensity, even where it is predicted that many-body effects might limit rate. Our observations are in good agreement two-body theory having no free parameters.
We compared three methods of stimulus preference assessment for verbal children and specifically evaluated the utility a choice procedure assessing relative reinforcer value. Using token system, five categories reinforcers, representing 15 different stimuli, was assessed by methods: survey, stimulus‐choice questionnaire, pictorial procedure. Results showed that assessments accurately identified high‐ low‐preference 3 4 participants. Survey results alone often rated multiple as high...
We present an experimental realization of a low-noise, phase-insensitive optical amplifier using four-wave mixing interaction in hot Rb vapor. Performance near the quantum limit for range gains, including unity, can be achieved. Such low-noise amplifiers are essential so-called cloning machines and useful information protocols. demonstrate that amplification ``cloning'' one half two-mode squeezed state is possible while preserving entanglement.
Research was conducted to ascertain if a combined repeated reading and question generation intervention effective at improving the achievement of fourth through eighth grade students with learning disabilities or who were risk for failure. Students assigned treatment control group via stratified random sampling. Instructional components training based on best practices reported in literature. receiving significantly improved their speed ability answer inferential comprehension questions...
We implement a noiseless optical amplifier using phase-sensitive four-wave mixing process in rubidium vapor. observe performance near the quantum limit for this type of over range experimental parameters and show that noise figure is always better than would be obtained with phase-insensitive same gain. Additionally, we supports hundreds spatial modes, making it possible to amplify complex two-dimensional patterns less 10% degradation input signal-to-noise ratio gains up 4.6. To confirm...
The SU(1,1) interferometer can be thought of as a Mach-Zehnder with its linear beam splitters replaced parametric nonlinear optical processes. We consider the cases bright- and vacuum-seeded interferometers using intensity or homodyne detectors. A simplified truncated scheme only one interaction is introduced, which not beats conventional detection bright seed, but saturate phase-sensitivity bound set by quantum Fisher information. also show that achieves sub-shot-noise phase sensitivity in...
From molecular spectroscopy of the Na2 purely long-range 0−g state we determine Na(3P) lifetime and measure predicted but previously unobserved effect retardation in interaction between two atoms. Our τ(P3/2) = 16.230(16) ns helps to remove a longstanding discrepancy experiment theory. Electron cloud overlap is unimportant (R > 55a0) spectrum calculated, ab initio, from atomic properties. By measuring binding energies 120 MHz correction due resonant-dipole R−3 confirmed.
We conducted functional analyses of classroom disruption during contingent teacher and peer attention conditions for 3 children with deficit hyperactivity disorder. Attention provided by confederates appeared to function as a distinct form positive reinforcement all children.
Homodyne detection is often used for interferometers based on nonlinear optical gain media. For the configuration of a seeded, 'truncated SU(1,1)' interferometer Anderson et al. (Phys. Rev. A 95, 063843 (2017)) showed how to optimize homodyne scheme and demonstrated theoretically that it can saturate quantum Cramer-Rao bound phase estimation. In this work we extend those results by taking into account loss in truncated SU(1,1) determining optimized measurement. Further, build experimentally...
Abstract Typical classroom management procedures designed to reduce instances of inappropriate social behavior (i.e., tattling and punishment systems) may adversely impact the development relations students with and/or emotional disorders. Two alternative where are encouraged monitor report incidental prosocial behaviors described research supporting their effectiveness in remedying preventing interaction problems within environments reviewed. Recommendations for future on altering so that...
We report a direct measurement of the ${\mathrm{Na}}_{2}$ $X^{1}\ensuremath{\Sigma}_{g}^{+}$ ground-state dissociation energy. Three spectroscopic measurements are combined to directly yield energy lowest ($v=0$) vibrational level relative free-atom limit. The $X^{1}\ensuremath{\Sigma}_{g}^{+}(v=0\ensuremath{\rightarrow}31)$ splitting is measured by double-resonance spectroscopy;...
We present experimental results on the generation of multi-spatial-mode, single-beam, quadrature squeezed light using four-wave mixing in hot Rb vapor. Squeezing and phase-sensitive deamplification are observed over a range powers detunings near (85)Rb D1 atomic transition. observe -3 dB vacuum squeezing, comparable to best single-spatial mode previously reported vapors, however, produced here multiple spatial modes. confirm that squeezing is more than one transverse by studying distribution...
We present experimental results showing that quantum correlated light can be produced using non-degenerate, off-resonant, four-wave mixing (4WM) on both the D1 (795 nm) and D2 (780 lines of (85)Rb (87)Rb, extending earlier work line (85)Rb. Using this 4WM process in a hot vapor cell to produce bright twin beams, we characterize degree intensity-difference noise reduction below standard limit for each four systems. Although system approximates double-lambda configuration, differences details...