Open Access. Powered by Scholars. Published by Universities.®
- Publication Year
- Publication
- Publication Type
- File Type
Articles 1 - 15 of 15
Full-Text Articles in Physics
Catalysis Of Stark-Tuned Interactions Between Ultracold Rydberg Atoms, A. L. Win, W. D. Williams, Thomas J. Carroll, C. I. Sukenik
Catalysis Of Stark-Tuned Interactions Between Ultracold Rydberg Atoms, A. L. Win, W. D. Williams, Thomas J. Carroll, C. I. Sukenik
Physics and Astronomy Faculty Publications
We have experimentally investigated a catalysis effect in the resonant energy transfer between ultracold 85Rb Rydberg atoms. We studied the time dependence of the process, 34p + 34p → 34s + 35s, and observed an enhancement of 34s state population when 34d state atoms are added.We have also performed numerical model simulations, which are in qualitative agreement with experiment and indicate that the enhancement arises from a redistribution of p-state atoms due to the presence of the d-state atoms.
Imaging The Dipole-Dipole Energy Exchange Between Ultracold Rubidium Rydberg Atoms, Donald P. Fahey, Thomas J. Carroll, Michael W. Noel
Imaging The Dipole-Dipole Energy Exchange Between Ultracold Rubidium Rydberg Atoms, Donald P. Fahey, Thomas J. Carroll, Michael W. Noel
Physics and Astronomy Faculty Publications
The long-range, anisotropic nature of the interaction among atoms in an ultracold dipolar gas leads to a rich array of possibilities for studying many-body physics. In this work, an ultracold gas of highly excited atoms is used to study energy transport due to the long-range dipole-dipole interaction. A technique is developed to measure both the internal energy states of the interacting Rydberg atoms and their positions in space. This technique is demonstrated by observing energy exchange between two spatially separated groups of Rydberg atoms excited to two different internal states. Simulations confirm the general features of the energy transport in …
Electric Dipole Moments And Polarizability In The Quark-Diquark Model Of The Neutron, Y. N. Srivastava, A. Widom, J. Swain, O. Panella
Electric Dipole Moments And Polarizability In The Quark-Diquark Model Of The Neutron, Y. N. Srivastava, A. Widom, J. Swain, O. Panella
John Swain
For a bound state internal wave function respecting parity symmetry, it can be rigorously argued that the mean electric dipole moment must be strictly zero. Thus, both the neutron, viewed as a bound state of three quarks, and the water molecule, viewed as a bound state of ten electrons two protons and an oxygen nucleus, both have zero mean electric dipole moments. Yet, the water molecule is said to have a nonzero dipole moment strength $d=e\Lambda $ with $\Lambda_{H_2O} \approx 0.385\ \dot{A}$. The neutron may also be said to have an electric dipole moment strength with $\Lambda_{neutron} \approx 0.612\ fm$. …
Effects Of Anomalous Charged Current Dipole Moments Of The Tau On The Decay $\Tau^-\To\Nu_\Tau\Pi^-\Pi^0$, Maria-Teresa Dova, Pablo Lacentre, John Swain, Lucas Taylor
Effects Of Anomalous Charged Current Dipole Moments Of The Tau On The Decay $\Tau^-\To\Nu_\Tau\Pi^-\Pi^0$, Maria-Teresa Dova, Pablo Lacentre, John Swain, Lucas Taylor
John Swain
We analyse the process $\tau^-\to\nu_\tau\pi^-\pi^0$ allowing for anomalous weak charged current magnetic and electric dipole moment interactions and determine the effects on the differential and total decay rates. Using recent experimental data we determine the following values for the anomalous magnetic and electric dipole moment parameters, respectively: $\kappa = 0.16 \pm 0.08; and |\tilde\kappa| = 0.88^{+0.25}_{-0.35}.$
Electric Dipole Moments And Polarizability In The Quark-Diquark Model Of The Neutron, Y. Srivastava, A. Widom, J. Swain, O. Panella
Electric Dipole Moments And Polarizability In The Quark-Diquark Model Of The Neutron, Y. Srivastava, A. Widom, J. Swain, O. Panella
Allan Widom
For a bound state internal wave function respecting parity symmetry, it can be rigorously argued that the mean electric dipole moment must be strictly zero. Thus, both the neutron, viewed as a bound state of three quarks, and the water molecule, viewed as a bound state of ten electrons two protons and an oxygen nucleus, both have zero mean electric dipole moments. Yet, the water molecule is said to have a nonzero dipole moment strength $d=e\Lambda $ with $\Lambda_{H_2O} \approx 0.385\ \dot{A}$. The neutron may also be said to have an electric dipole moment strength with $\Lambda_{neutron} \approx 0.612\ fm$. …
Simulations Of The Dipole-Dipole Interaction Between Two Spatially Separated Groups Of Rydberg Atoms, Thomas J. Carroll, Christopher Daniel, Leah Hoover, Timothy Sidie, Michael W. Noel
Simulations Of The Dipole-Dipole Interaction Between Two Spatially Separated Groups Of Rydberg Atoms, Thomas J. Carroll, Christopher Daniel, Leah Hoover, Timothy Sidie, Michael W. Noel
Physics and Astronomy Faculty Publications
The dipole-dipole interaction among ultracold Rydberg atoms is simulated. We examine a general interaction scheme in which two atoms excited to the x and x states are converted to y and y states via a Förster resonance. The atoms are arranged in two spatially separated groups, each consisting of only one species of atom. We monitor the state mixing by recording the fraction of atoms excited to the y state as the distance between the two groups is varied. With zero detuning a many-body effect that relies on always resonant interactions causes the state mixing to have a finite range. …
Electric Multipole Moments Of Some Diatomic Molecules Molecules, M. Özgür Sezer, Ayhan Özmen, Hüseyi̇n Yüksel
Electric Multipole Moments Of Some Diatomic Molecules Molecules, M. Özgür Sezer, Ayhan Özmen, Hüseyi̇n Yüksel
Turkish Journal of Physics
Molecular Electric Multipole Moment (MEMM) integrals have been derived for diatomic molecular systems, and then some lower multipole moments as dipole moments and quadrupole moments have been calculated for some diatomic molecules. The calculations have been performed by using our analytical formula over Slater-Type orbitals (STOs) with Cade and Huo's basis sets and the GAMESS program package working with Gaussian-Type basis sets (GTOs). The expressions which involve factorials are given in terms of binomial coefficients in order to speed up calculations. The results have been obtained in agreement with data found in the literature.
Angular Dependence Of The Dipole-Dipole Interaction In A Nearly One-Dimensional Sample Of Rydberg Atoms, Thomas J. Carroll, Katharine Claringbould, Anne Goodsell, M. J. Lim, Michael W. Noel
Angular Dependence Of The Dipole-Dipole Interaction In A Nearly One-Dimensional Sample Of Rydberg Atoms, Thomas J. Carroll, Katharine Claringbould, Anne Goodsell, M. J. Lim, Michael W. Noel
Physics and Astronomy Faculty Publications
Atoms in an ultracold highly excited sample are strongly coupled through the dipole-dipole interaction. In an effort to understand and manipulate the complicated interactions in this system we are investigating their dependence on the relative orientation of the dipoles. By focusing a 480 nm beam from a tunable dye laser into a magneto-optical trap, we produce a nearly one-dimensional sample of Rydberg atoms. The trap lies at the center of four conducting rods with which we can vary the magnitude and direction of the electric field at the trap, thus controlling the orientation of the dipoles with respect to the …
Dynamical Theory For Modeling Dipole-Dipole Interactions In A Microcavity: The Green Dyadic Approach, P.T. Leung, R. L. Hartman
Dynamical Theory For Modeling Dipole-Dipole Interactions In A Microcavity: The Green Dyadic Approach, P.T. Leung, R. L. Hartman
Physics Faculty Publications and Presentations
A dynamical theory for modeling the dipole-dipole interaction in a microcavity is formulated using the Green dyadic approach. To our knowledge, this theory is one of the most general in many aspects of modeling the phenomenon. It accommodates an arbitrary number of layers adjacent to the cavity, constant but arbitrary dielectric properties within each layer, inclusion of retardation effects, arbitrary dipole orientations, and an unlimited number of interacting dipoles. Numerical results for the emission properties of interacting molecular dipoles in a microcavity are presented to illustrate the capability of the method.
Frequency Shifts Of Molecules At Rough Metal Surfaces, M. H. Hider, P.T. Leung
Frequency Shifts Of Molecules At Rough Metal Surfaces, M. H. Hider, P.T. Leung
Physics Faculty Publications and Presentations
The frequency shifts for dipolar transitions of molecules at rough metallic surfaces are studied in a phenomenological model following the approach of the authors' previous work [Phys. Rev. B 36, 4664 (1987)], with the surface roughness modeled by a shallow grating profile in most cases. The main findings here are as follows: (1) such surface-induced shifts are indeed observable for molecular frequencies away from the surface-plasmon resonance frequency of the metal; (2) the presence of surface roughness can either enhance or suppress the flat-surface-induced shifts, leading to extra morphology-dependent resonances originated from the radiative coupling between the molecular emission and …
Dielectric Constant In Fluids Of Classical Deformable Molecules, John D. Ramshaw
Dielectric Constant In Fluids Of Classical Deformable Molecules, John D. Ramshaw
Physics Faculty Publications and Presentations
Classical statistical mechanical description of dielectric fluids is further discussed. Dipole moment correlations of polarizable molecules are discussed.
Existence Of The Dielectric Constant In Fluids Of Classical Deformable Molecules, John D. Ramshaw
Existence Of The Dielectric Constant In Fluids Of Classical Deformable Molecules, John D. Ramshaw
Physics Faculty Publications and Presentations
The existence of the dielectric constant epsilon is investigated for fluids composed of classical deformable (polarizable) molecules. The development is based upon generalized functional-derivative relations which involve joint distributions in molecular positions r/sub k/ and dipole moments ..mu../sub k/. Sufficient conditions for the existence of epsilon are expressed in terms of the generalized direct correlation function c(12) = c(r/sub 1/, ..mu../sub 1/; r/sub 2/, ..mu../sub 2/). It is found that epsilon exists if -kTc(12) depends only on relative positions and dipole moment directions (in addition to Vertical Bar..mu../sub 1/Vertical Bar and Vertical Bar..mu../sub 2/Vertical Bar), and becomes asymptotic to the …
Comments On The Theory Of Dipolar Fluids, John D. Ramshaw
Comments On The Theory Of Dipolar Fluids, John D. Ramshaw
Physics Faculty Publications and Presentations
The theory of dipolar fluids posbulated by Chan, Mitchell and Ninham is commented upon.
Existence Of The Dielectric Constant In Fluids Of Nonlinear Rigid Polar Molecules, John D. Ramshaw
Existence Of The Dielectric Constant In Fluids Of Nonlinear Rigid Polar Molecules, John D. Ramshaw
Physics Faculty Publications and Presentations
The existence of the dielectric constant epsilon is investigated for fluids composed of nonlinear rigid polar molecules. The investigation is performed using the functional-derivative approach previously employed to establish sufficient conditions for the existence of epsilon in fluids of linear (axially symmetric) molecules. It is shown that these same conditions are sufficient for nonlinear molecules of arbitrary symmetry. An expression for epsilon in terms of the direct correlation function emerges automatically from the development. This expression, which involves the inversion of a 3 x 3 matrix, is a slight generalization of one obtained earlier by Hoye and Stell using an …
Existence Of The Dielectric Constant In Rigid-Dipole Fluids: The Direct Correlation Function, John D. Ramshaw
Existence Of The Dielectric Constant In Rigid-Dipole Fluids: The Direct Correlation Function, John D. Ramshaw
Physics Faculty Publications and Presentations
The question of whether the dielectric constant ε exists (is well defined) for a finite fluid system of rigid dipolar molecules is reconsidered and reformulated. It is found that this question can most simply be expressed in terms of the behavior of the position‐ and orientation‐dependent direct correlation function c(r1,ω1; r2, ω2). It is shown that ε exists if c satisfies the following two conditions: (a) c~–φ/kT for |r1–r2|>σ, where φ is the dipole‐dipole potential and σ is a length which is large microscopically but small macroscopically. …