Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review Letters

Measurement of the Density Matrix of a Longitudinally Modulated Atomic Beam

Richard A. Rubenstein, David A. Kokorowski, Al-Amin Dhirani, Tony Roberts, Subhadeep Gupta, Jana Lehner, W. W. Smith, Edward T. Smith, Herbert Joseph Bernstein, David E. Pritchard

Published Sep 20, 1999• 11 citations
Publisher

Abstract

We present the first measurement of the longitudinal density matrix of a matter-wave beam. Using a unique interferometric scheme, both the amplitude and phase of off-diagonal density matrix elements were determined directly, without the use of traditional tomographic techniques. The measured density matrix of a doubly amplitude modulated atomic sodium beam compares well with theoretical predictions.

DOI
10.1103/physrevlett.83.2285

Related papers

Search for Off-Diagonal Density Matrix Elements for Atoms in a Supersonic Beam

Richard A. Rubenstein, Al-Amin Dhirani, David A. Kokorowski +7 more

We demonstrate the absence of off-diagonal elements for the density matrix of a supersonic Na atomic beam, thus showing that there are no coherent wave packets emerging from this source. We used a differentially detuned separated oscillatory field longitudinal interferometer to search for off-diagonal density matrix elements in the longitudinal energy/momentum basis. Our study places a stringent lower bound on their possible size over an off-diagonal energy range from 0 to 100 kHz.

Physical Review Letters•Mar 8, 1999•19 citations

Longitudinal quantum beam tomography

David A. Kokorowski, David E. Pritchard

We propose an experiment to determine the density operator for the longitudinal quantum state of an atomic beam. The method is based on tomographic reconstruction of the Wigner function via a set of measured probability distributions for the phase-space rotated position operator. The time evolution of the Wigner function in free space effectively performs the required phase-space rotation. We propose a state-selective time-dependent technique for measuring longitudinal probability distributions.

Journal of Modern Optics•Nov 1, 1997•12 citations

Atomic beam propagation effects: index of refraction and longitudinal tomography

David A. Kokorowski, Troy D. Hammond, Edward T. Smith +4 more

We present initial measurements of the dispersive index of refraction for sodium matter waves passing through argon. In addition, we describe a novel scheme for performing tomography on the longitudinal quantum state of particles in an atomic beam.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 1, 1997•0 citations

Longitudinal Atom Interferometry

David A. Kokorowski, Tony Roberts, Richard A. Rubenstein +2 more

A detuned, radiofrequency field interacting with atoms in an atomic beam constitutes a beamsplitter in longitudinal momentum space. Using such beamsplitters, we have constructed a longitudinal atom interferometer in a generalization of Ramsey's classic SOF configuration. This interferometer is well-suited to studying the longitudinal coherence properties of matter-wave beams. We report on two such experiments, including a deconvolution of the longitudinal density matrix of an atomic beam, and a search for longitudinal coherences coming from our supersonic beam source.

Fortschritte der Physik•May 1, 2000•4 citations

Determining the density matrix of a molecular beam using a longitudinal matter wave interferometer

Al-Amin Dhirani, David A. Kokorowski, Richard A. Rubenstein +5 more

Two separated oscillatory fields, if tuned to different frequencies, can generate or interrogate longitudinal momentum coherences in a beam of two-state particles. We demonstrate that use of differentially detuned separated oscillatory fields is an efficient method to determine the longitudinal density matrix of a particle beam.

Journal of Modern Optics•Nov 1, 1997•14 citations

Longitudinal atom optics : measuring the density matrix of a matter wave beam

Richard A. Rubenstein

•Jan 1, 1999•2 citations
We present the first measurement of the longitudinal density matrix of a matter-wave beam. Using a unique interferometric scheme, both the amplitude and phase of off-diagonal density matrix elements were determined directly, without the use of traditional tomographic techniques. The measured density matrix of a doubly amplitude modulated atomic sodium beam compares well with theoretical predictions.
A detuned, radiofrequency field interacting with atoms in an atomic beam constitutes a beamsplitter in longitudinal momentum space. Using such beamsplitters, we have constructed a longitudinal atom interferometer in a generalization of Ramsey's classic SOF configuration. This interferometer is well-suited to studying the longitudinal coherence properties of matter-wave beams. We report on two such experiments, including a deconvolution of the longitudinal density matrix of an atomic beam, and a search for longitudinal coherences coming from our supersonic beam source.