18 research outputs found
Phase Space Tomography of Classical and Nonclassical Vibrational States of Atoms in an Optical Lattice
Atoms trapped in optical lattice have long been a system of interest in the
AMO community, and in recent years much study has been devoted to both short-
and long-range coherence in this system, as well as to its possible
applications to quantum information processing. Here we demonstrate for the
first time complete determination of the quantum phase space distributions for
an ensemble of atoms in such a lattice, including a negative Wigner
function for atoms in an inverted state.Comment: Submitted to Journal of Optics B: Quantum and Semiclassical Optics.
Special issue in connection with the 9th International Conference on Squeezed
States and Uncertainty Relations, to be held in Besancon, France, on 2-6 May
200
An Examination of the Noken and Indigenous Cultural Identity: Voices of Papuan Women
Noken is an essential tool/bag/clothing in the lives of Indigenous people of West Papua, which is made from knitting thin strips of wood primarily from the Gnetum Gnemon tree. Raw materials required to make noken have become scarce due to massive deforestation. An analysis of the noken lends itself to a useful understanding of the link between economic development initiatives in the Merauke Regency of West Papua and shifting cultural identity among Indigenous Papuans. Drawing on the Women, Culture and Development (WCD) approach, this qualitative study examines interviews from Papuan women in order to understand how the noken resonates with Indigenous Papuans, and how perceptions of noken and their accessibility have changed. The findings reveal that a combination of factors contribute to dwindling noken supplies, which adversely impact Papuansâ ability to produce and reproduce their culture. This paper argues that Papuan women possess an unwritten specialized knowledge that is of increased value in a shifting social context and hold new meaning in response to competing influences of non-Papuans
Observation of high-order quantum resonances in the kicked rotor
Quantum resonances in the kicked rotor are characterized by a dramatically
increased energy absorption rate, in stark contrast to the momentum
localization generally observed. These resonances occur when the scaled
Planck's constant hbar=(r/s)*4pi, for any integers r and s. However only the
hbar=r*2pi resonances are easily observable. We have observed high-order
quantum resonances (s>2) utilizing a sample of low temperature, non-condensed
atoms and a pulsed optical standing wave. Resonances are observed for
hbar=(r/16)*4pi r=2-6. Quantum numerical simulations suggest that our
observation of high-order resonances indicates a larger coherence length than
expected from an initially thermal atomic sample
Anomalous diffusion in the resonant quantum kicked rotor
We study the resonances of the quantum kicked rotor subjected to an
excitation that follows a deterministic time-dependent prescription. For the
primary resonances we find an analytical relation between the long-time
behavior of the standard deviation and the external kick strength. For the
secondary resonances we obtain essentially the same result numerically.
Selecting the time sequence of the kick allows to obtain a variety of
asymptotic wave-function spreadings: super-ballistic, ballistic, sub-ballistic,
diffusive, sub-diffusive and localized.Comment: 5 pages, 3 figures To appear in Physica A
Coherent acceleration of material wavepackets in modulated optical fields
We study the quantum dynamics of a material wavepacket bouncing off a
modulated atomic mirror in the presence of a gravitational field. We find the
occurrence of coherent accelerated dynamics for atoms beyond the familiar
regime of dynamical localization. The acceleration takes place for certain
initial phase space data and within specific windows of modulation strengths.
The realization of the proposed acceleration scheme is within the range of
present day experimental possibilities
Stark deceleration of CaF molecules in strong- and weak-field seeking states
We report the Stark deceleration of CaF molecules in the strong-field seeking
ground state and in a weak-field seeking component of a rotationally-excited
state. We use two types of decelerator, a conventional Stark decelerator for
the weak-field seekers, and an alternating gradient decelerator for the
strong-field seekers, and we compare their relative merits. We also consider
the application of laser cooling to increase the phase-space density of
decelerated molecules.Comment: 10 pages, 8 figure
Lifetime of the A(v(')=0) state and Franck-Condon factor of the A-X(0-0) transition of CaF measured by the saturation of laser-induced fluorescence
We describe a method for determining the radiative decay properties of a
molecule by studying the saturation of laser-induced fluorescence and the
associated power broadening of spectral lines. The fluorescence saturates
because the molecules decay to states that are not resonant with the laser. The
amplitudes and widths of two hyperfine components of a spectral line are
measured over a range of laser intensities and the results compared to a model
of the laser-molecule interaction. Using this method we measure the lifetime of
the A(v'=0) state of CaF to be tau=19.2 \pm 0.7 ns, and the Franck-Condon
factor for the transition to the X(v=0) state to be Z=0.987 (+0.013 || -0.019).
In addition, our analysis provides a measure of the hyperfine interval in the
lowest-lying state of A(v'=0), Delta_e=4.8 \pm 1.1 MHz.Comment: 10 pages, 6 figures. Minor revisions following referee suggestion