Threshold and linewidth of a mirrorless parametric oscillator

We analyze the above-threshold behavior of a mirrorless parametric oscillator based on resonantly enhanced four wave mixing in a coherently driven dense atomic vapor. It is shown that, in the ideal limit, an arbitrary small flux of pump photons is sufficient to reach the oscillator threshold. We demonstrate that due to the large group-velocity delays associated with coherent media, an extremely narrow oscillator linewidth is possible, making a narrow-band source of non-classical radiation feasible.Comment: revised version to appear in Phys.Rev.Lett., contains discussion on threshold conditions and operation on few-photon leve

Raman Adiabatic Transfer of Optical States

We analyze electromagnetically induced transparency and light storage in an ensemble of atoms with multiple excited levels (multi-Lambda configuration) which are coupled to one of the ground states by quantized signal fields and to the other one via classical control fields. We present a basis transformation of atomic and optical states which reduces the analysis of the system to that of EIT in a regular 3-level configuration. We demonstrate the existence of dark state polaritons and propose a protocol to transfer quantum information from one optical mode to another by an adiabatic control of the control fields

Factors and mechanisms of productive secondary reservoirs formation in deep-lying oil and gas complexes. Article 1. Tectonophysical mechanisms of Lower Carboniferous quartzite-sandstones decompaction in the central part of the Dniprovsko-Donetska depression at the depths of more than 4.5 km

In the world, the scale of development of secondary reservoirs in decompaction rock bodies in a wide formation range is steadily increasing: from the crystalline basement of different ages of various oil and gas-bearing basins to terrigenous deposits with reduced primary porosity and carbonate formations. Development of hydrocarbon resources associated with secondary reservoirs of deep-seated complexes is the most important strategic direction of geological exploration. The results presented in this article are of fundamental importance, since they are based, firstly, mainly on the study of the core of deep-lying complexes, and secondly, on a significantly different (than in previous works) methodology (wide application of electron microscopic scanning with X-ray spectral probing and diffractometry), thirdly (and most importantly) – on a significantly different ideology. It is based on the concept of different genetic types of post-sedimentation transformations. Along with diagenesis and catagenesis, it is dislocation epigenesis and hypogene allogenesis with specific geodynamic and geothermodynamic regimes, including the special role of structural temperatures and pressures. In oil and gas-bearing basins of the continental-riftogenic (aulacogenic) type, the final stage of regional epigenesis is dislocation epigenesis with zonal and local manifestation of hypogene allogenesis. Gas and gas condensate deposits, as well as the main part of oil and heterophase deposits, are associated with this stage. The established regularities of the formation of secondary reservoirs are of particular importance for the effective development of the hydrocarbon potential of great depths

Mesoscopic Cavity Quantum Electrodynamics with Quantum Dots

We describe an electrodynamic mechanism for coherent, quantum mechanical coupling between spacially separated quantum dots on a microchip. The technique is based on capacitive interactions between the electron charge and a superconducting transmission line resonator, and is closely related to atomic cavity quantum electrodynamics. We investigate several potential applications of this technique which have varying degrees of complexity. In particular, we demonstrate that this mechanism allows design and investigation of an on-chip double-dot microscopic maser. Moreover, the interaction may be extended to couple spatially separated electron spin states while only virtually populating fast-decaying superpositions of charge states. This represents an effective, controllable long-range interaction, which may facilitate implementation of quantum information processing with electron spin qubits and potentially allow coupling to other quantum systems such as atomic or superconducting qubits.Comment: 8 pages, 5 figure

Parametric Self-Oscillation via Resonantly Enhanced Multiwave Mixing

We demonstrate an efficient nonlinear process in which Stokes and anti-Stokes components are generated spontaneously in a Raman-like, near resonant media driven by low power counter-propagating fields. Oscillation of this kind does not require optical cavity and can be viewed as a spontaneous formation of atomic coherence grating