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