Semiconductor cavity QED: Bandgap induced by vacuum fluctuations

We consider theoretically a semiconductor nanostructure embedded in one-dimensional microcavity and study the modification of its electron energy spectrum by the vacuum fluctuations of the electromagnetic field. To solve the problem, a non-perturbative diagrammatic approach based on the Green's function formalism is developed. It is shown that the interaction of the system with the vacuum fluctuations of the optical cavity opens gaps within the valence band of the semiconductor. The approach is verified for the case of large photon occupation numbers, proving the validity of the model by comparing to previous studies of the semiconductor system excited by a classical electromagnetic field. The developed theory is of general character and allows for unification of quantum and classical descriptions of the strong light-matter interaction in semiconductor structures

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The chamber was a turmoil of ripping, snarling, and tearing as Quesa struggled and swore. She fought back hot tears of pain and rage while the fur flew fast and shrill cries rent the air

Economic analysis of potato, corn, and wheat response to nitrogen and phosphorus application in the highlands of Ecuador

"Objectives: 1. To predict a production function relating the effects of topdress nitrogen and phosphorus on potato yield. 2. Estimate the resulting yield of potatoes per hectare for specified nitrogen and phosphorus applications. 3. Calculate the combinations of nitrogen and phosphorous required to produce specified yields (iso - quants) of potatoes and corresponding marginal rates of substitution. 4. To estimate the optimum level of application of one nutrient when the level of the other is considered to be fixed at different levels and with specific potato price relationships. 5. Estimate the minimum cost combinations of nitrogen and phosphorus for specified potato yield levels and varying price ratios. 6. Determine the optimun combination of nutrients (nitrogen and phosphorus) for specific potato price relationships. 7. Estimate the production function and the optimun combination of nutrients for current price relationships for corn and wheat."--Page 12.Includes bibliographical references

3-dimensional Rules for Finite-Temperature Loops

We present simple diagrammatic rules to write down Euclidean n-point functions at finite temperature directly in terms of 3-dimensional momentum integrals, without ever performing a single Matsubara sum. The rules can be understood as describing the interaction of the external particles with those of the thermal bath.Comment: 12 pages, 4 figures, to appear in Physics Letters

Neutrino emission rates in highly magnetized neutron stars revisited

Magnetars are a subclass of neutron stars whose intense soft-gamma-ray bursts and quiescent X-ray emission are believed to be powered by the decay of a strong internal magnetic field. We reanalyze neutrino emission in such stars in the plausibly relevant regime in which the Landau band spacing of both protons and electrons is much larger than kT (where k is the Boltzmann constant and T is the temperature), but still much smaller than the Fermi energies. Focusing on the direct Urca process, we find that the emissivity oscillates as a function of density or magnetic field, peaking when the Fermi level of the protons or electrons lies about 3kT above the bottom of any of their Landau bands. The oscillation amplitude is comparable to the average emissivity when the Landau band spacing mentioned above is roughly the geometric mean of kT and the Fermi energy (excluding mass), i. e., at fields much weaker than required to confine all particles to the lowest Landau band. Since the density and magnetic field strength vary continuously inside the neutron star, there will be alternating surfaces of high and low emissivity. Globally, these oscillations tend to average out, making it unclear whether there will be any observable effects.Comment: 7 pages, 2 figures; accepted for publication in Astronomy & Astrophysic

Comprehensive study of Leon-Queretaro area

There are no author-identified significant results in this report

BCS pairing in fully repulsive fermion mixtures

We consider a mixture of two neutral cold Fermi gases with repulsive interactions. We show that in some region of the parameter space of the system the effective attraction between fermions of the same type can appear due to the exchange of collective excitations. This leads to the formation of BCS pairing in the case where bare inter-atomic interactions are repulsive

Awareness Of Racial And Ethnic Health Disparities Has Improved Only Modestly Over A Decade

Abstract available at publisher's web site.http://dx.doi.org/10.1377/hlthaff.2010.070

Heisenberg quantization for the systems of identical particles and the Pauli exclusion principle in noncommutative spaces

We study the Heisenberg quantization for the systems of identical particles in noncommtative spaces. We get fermions and bosons as a special cases of our argument, in the same way as commutative case and therefore we conclude that the Pauli exclusion principle is also valid in noncommutative spaces.Comment: 8 pages, 1 figur