13,477 research outputs found
Knight Shift in the FFLO State of a Two-Dimensional D-Wave Superconductor
We report on the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state in
two-dimensional d-wave superconductors with magnetic field parallel to the
superconducting planes. This state occurs at high magnetic field near the
Pauli-Clogston limit and is a consequence of the competition between the pair
condensation and Zeeman energy. We use the quasiclassical theory to
self-consistently compute the spatially nonuniform order parameter. Our
self-consistent calculations show that the FFLO state of a d-wave order
parameter breaks translational symmetry along preferred directions. The
orientation of the nodes in real space is pinned by the nodes of the basis
function in momentum space. Here, we present results for the Knight shift and
discuss the implications for recent nuclear magnetic resonance measurements on
CeCoIn5.Comment: 2 pages, 3 figures: LT-24 Conference, Orlando, Aug. 2005; to appear
in AIP Conference Proceeding
Mars Orbiter Laser Altimeter: Experiment summary after the first year of global mapping of Mars
The Mars Orbiter Laser Altimeter (MOLA), an instrument on the Mars Global Surveyor spacecraft, has measured the topography, surface roughness, and 1.064-μm reflectivity of Mars and the heights of volatile and dust clouds. This paper discusses the function of the MOLA instrument and the acquisition, processing, and correction of observations to produce global data sets. The altimeter measurements have been converted to both gridded and spherical harmonic models for the topography and shape of Mars that have vertical and radial accuracies of ~1 m with respect to the planet's center of mass. The current global topographic grid has a resolution of 1/64° in latitude × 1/32° in longitude (1 × 2 km^2 at the equator). Reconstruction of the locations of incident laser pulses on the Martian surface appears to be at the 100-m spatial accuracy level and results in 2 orders of magnitude improvement in the global geodetic grid of Mars. Global maps of optical pulse width indicative of 100-m-scale surface roughness and 1.064-μm reflectivity with an accuracy of 5% have also been obtained
Superpositions of the Orbital Angular Momentum for Applications in Quantum Experiments
Two different experimental techniques for preparation and analyzing
superpositions of the Gaussian and Laguerre-Gassian modes are presented. This
is done exploiting an interferometric method on the one hand and using computer
generated holograms on the other hand. It is shown that by shifting the
hologram with respect to an incoming Gaussian beam different superpositions of
the Gaussian and the Laguerre-Gaussian beam can be produced. An analytical
expression between the relative phase and the amplitudes of the modes and the
displacement of the hologram is given. The application of such orbital angular
momenta superpositions in quantum experiments such as quantum cryptography is
discussed.Comment: 18 pages, 4 figures. to appear in Journal of Optics
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