2,509 research outputs found
From EIT photon correlations to Raman anti-correlations in coherently prepared Rb vapor
We have experimentally observed switching between photon-photon correlations
(bunching) and anti-correlations (anti-bunching) between two orthogonally
polarized laser beams in an EIT configuration in Rb vapor. The bunching and
anti-bunching sswitching occurs at a specific magnetic field strength.Comment: 4 pages and 3 figure
Electromagnetically induced coherent backscattering
We demonstrate a strong coherent backward wave oscillation using forward
propagating fields only. This is achieved by applying laser fields to an
ultra-dispersive medium with proper chosen detunings to excite a molecular
vibrational coherence that corresponds to a backward propagating wave. The
physics then has much in common with propagation of ultra-slow light.
Applications to coherent scattering and remote sensing are discussed
Cooperative behavior of qutrits with dipole-dipole interactions
We have identified a class of many body problems with analytic solution
beyond the mean-field approximation. This is the case where each body can be
considered as an element of an assembly of interacting particles that are
translationally frozen multi-level quantum systems and that do not change
significantly their initial quantum states during the evolution. In contrast,
the entangled collective state of the assembly experiences an appreciable
change. We apply this approach to interacting three-level systems.Comment: 5 pages, 3 figures. Minor correction
Dissipationless electron transport in photon-dressed nanostructures
It is shown that the electron coupling to photons in field-dressed
nanostructures can result in the ground electron-photon state with a nonzero
electric current. Since the current is associated with the ground state, it
flows without the Joule heating of the nanostructure and is nondissipative.
Such a dissipationless electron transport can be realized in strongly coupled
electron-photon systems with the broken time-reversal symmetry - particularly,
in quantum rings and chiral nanostructures dressed by circularly polarized
photons.Comment: 4 pages; 1 figure; published versio
Quantum Rabi model for N-state atoms
A tractable N-state Rabi Hamiltonian is introduced by extending the parity
symmetry of the two-state model. The single-mode case provides a few-parameter
description of a novel class of periodic systems, predicting that the ground
state of certain four-state atom-cavity systems will undergo parity change at
strong coupling. A group-theoretical treatment provides physical insight into
dynamics and a modified rotating wave approximation obtains accurate analytical
energies. The dissipative case can be applied to study excitation energy
transfer in molecular rings or chains.Comment: 5 pages, 3 figures + supplement (2 pages); to appear in Phys. Rev.
Let
Geology and petrochemistry of the Mount Chase massive sulfide prospect, Penobscot County, Maine
The Mount Chase massive sulfide prospect of northern Penobscot County, Maine was discovered in 1979 by Getty Mining Company. The deposit occurs within a sequence of lower paleozoic metavolcanic and metasedimentary rocks. The footwall units consist of rhyolitic flows, quartz-feldspar crystal tuff, and altered tuffaceous volcanic breccias. These rocks lie unconformably upon intensely folded sediments which are tentatively correlated with the Grand Pitch Formation of probable Cambrian age. The footwall volcanoclastic rocks exhibit a narrow zone of intense chloritic alteration immediately below the massive sulfide horizon, and a broader zone of sericitic alteration below that. A zone of stringer mineralization is associated with the footwall alteration beneath the western side of the deposit. The massive sulfide occurs in two adjacent main lenses occurring approximately within the same stratigraphic horizon. On a microscopic scale, the sulfide minerals exhibit metamorphic recrystallization with porphyroblastic and poikilobastic textures common. The Mount Chase hanging wall units consist of a sequence of relatively unaltered crystal-lithic tuffs, greenstone, and shale. The entire Mount Chase footwall and hanging wall sequence is tentatively correlated with the early to middle Ordovician Shin Brook Formation.
Representative drill core samples were analyzed by x-ray fluorescence for SiO2, Al2O3, Fe2O3, MgO, Na2O, K2O, TiO2, P2O5, MnO, FeS2, Ba, Cu, Zn, Rb, and Sr. The chemical systems of Bastin and Ossan indicate a combination of metasedimentary and metavolcanic lithologies for the Mount Chase rocks. These results agreed well with mineralogical and textural interpretations. Harker-type variation diagrams indicate depleted levels of CaO, and somewhat elevated levels of Na2O. K2O is generally depleted in the hanging wall rocks and elevated in the footwall rocks. These observations are interpreted to be the result of alkali metasomatism in the hanging wall rocks and a combination of alkali metasomatism and hydrothermal alteration in the footwall rocks. TAS and AFM plots of the Mount Chase igneous rocks indicate subalkalic calc-alkaline affinities though the most mafic rocks plot as tholeiites --Abstract, pages ii-iii
Feedback effects on the current correlations in Y-shaped conductors
We study current fluctuations in a Y-shaped conductor connected to external
leads with finite impedances. We show that, due to voltage fluctuations in the
circuit, the moments of the transferred charges cannot be obtained from simple
rescaling of the bare values already in the second moments. The
cross-correlation between the output terminals can change from negative to
positive under certain parameter regimes.Comment: 4 pages, figures attached separatel
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