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Search Publications by: Charles W Clark (Assoc)

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Displaying 151 - 175 of 225

Accelerating Scientific Discovery through Computation and Visualization

November 1, 2000
Author(s)
James S. Sims, John G. Hagedorn, Peter M. Ketcham, Steven G. Satterfield, Terence J. Griffin, William L. George, H A. Fowler, B A. am Ende, Howard Hung, Robert B. Bohn, John E. Koontz, Nicos Martys, Charles E. Bouldin, James A. Warren, D L. Feder, Charles W. Clark, Bernard J. Filla, Judith E. Terrill
The rate of scientific discovery can be accelerated through computation and visualization. This acceleration results from the synergy of expertise, computing tools, and hardware for enabling high performance computation, information science, and

Dark-Soliton States of Bose Einstein Condensates in Anisotropic Traps

November 1, 2000
Author(s)
D Feder, M S. Pindzola, L A. Collins, B I. Schneider, Charles W. Clark
Dark soliton states of Bose-Einstein condensates in anisotropic traps are studied by direct solution of the time-dependent Gross-Pitaevskii equation in three dimensions. The ground and self-consistent excited states for a completely anisotropic harmonic

Detection of the BCS Transition of a Trapped Fermi-Gas

October 1, 2000
Author(s)
G M. Bruun, Charles W. Clark
We investigate theoretically the properties of a trapped gas of fermionic atoms both in the normal and the superfluid phase. A detailed analysis including the shell structure of the normal phase spectrum exactly, leads to the proposal of two observables

Imaging the Phase of an Evolving Bose-Einstein Condensate Wave Function

September 1, 2000
Author(s)
J E. Simsarian, J Denschlag, M Edwards, Charles W. Clark, Lu Deng, Edward W. Hagley, Kristian Helmerson, S L. Rolston, William D. Phillips
We demonstrate a spatially resolved autocorrelation measurement with a Bose-Einstein condensate (BEC) and measure the evolution of the spatial profile of its quantum mechanical phase. After releasing the BEC from the magnetic trap, the phase develops a

Ideal Gases in Time-Dependent Traps

June 1, 2000
Author(s)
G M. Bruun, Charles W. Clark
We investigate theoretically the properties of an ideal trapped gas in a time-dependent harmonic potential. Using a scaling formalism, we are able to present exact analytical results for two important classes of experiments: free expansion of the gas upon

Gapless Mean-Field Theory of Bose-Einstein Condensation

January 15, 2000
Author(s)
D A. Hutchinson, Karen G. Burnett, K Dodd, S A. Morgan, M Rusch, M Zaremba, N P. Proukakis, A Griffin, Mark A. Edwards, Charles W. Clark
We present a topical review of the development of finite-temperature field theories of Bose-Einstein condensation in weakly interacting atomic gases. We highlight the difficulties in obtaining a consistent finite-temperature theory that has a gapless

Generating Solitons by Phase Engineering of a Bose-Einstein Condensate

January 1, 2000
Author(s)
J Denschlag, J E. Simsarian, D L. Feder, Charles W. Clark, L A. Collins, J Cubizolles, Lu Deng, Edward W. Hagley, Kristian Helmerson, W P. Reinhardt, S L. Rolston, B I. Schneider, William D. Phillips
We demonstrate quantum phase engineering using two novel techniques that allow us to write and read the spatial phase of a Bose-Einstein condensate (BEC). We design and produce a quantum state by optically imprinting phasepatterns onto a condensate of

Nucleation of Vortez Arrays in Rotating Anisotropic Bose-Einstein Condensates

January 1, 2000
Author(s)
D L. Feder, Charles W. Clark, B I. Schneider
The nucleation of vortices and the resulting structures of vortex arrays in dilute, trapped, zero-temperature Bose-Einstein condensates are investigated numerically. Vortices are generated by rotating a three-dimensional, anisotropic harmonic atom trap

Hydrodynamic Excitations for a Trapped Fermi Gas

December 1, 1999
Author(s)
G M. Bruun, Charles W. Clark
We discuss collective excitations of a trapped dilute Fermi gas within a hydrodynamic approximation. Analytical results are derived for both high- and low -temperature limits and are applied to 40K and 6Li systems of current experimental interest. We

Temporal, Matter-Wave Dispersion Talbot Effect

December 1, 1999
Author(s)
Lu Deng, Edward W. Hagley, J Denschlag, J E. Simsarian, M Edwards, Charles W. Clark, Kristian Helmerson, S L. Rolston, William D. Phillips
We analyze and experimentally demonstrate a new (temporal) Talbot effect, where a pulsed phase grating is applied to a cloud of cold atoms (Bose-Einstein condensate). In contrast to the usual (spatial) Talbot effect, our atoms gain kinetic energy when

The Theory of Bose-Einstein Condensation of Dilute Gases

December 1, 1999
Author(s)
Karen G. Burnett, M Edwards, Charles W. Clark
In this article, we present a current perspective on advances in the theoretical understanding of Bose-Einstein condensation from the standpoint of atomic, molecular and optical (AMO) physics. In AMO physics, BEC has come to be perceived both as an

Non-Self-Similar Modes of Vibration of a Bose-Einstein Condensate

September 1, 1999
Author(s)
M Brewczyk, Charles W. Clark, M Lewenstein, K Rzazewski
A hydrodynamical version of the time-dependent Gross-Pitaevskii equation is used to describe driven vibrations of a Bose-Einstein condensate of 87Rb atoms in a magnetic trap. If the trap frequency is suddenly decreased, and later is suddenly returned to