Lucht Probst Associates (Germany)

Bezugszeit: Das Abonnement gilt zunächst für ein Jahr; es verlängert sich, wenn nicht drei Monate vor Ablauf dieses Jahres schriftlich gekündigt wird.Darüber hinaus sind Kündigungen jeweils drei Monate vor Jahresende der Abonnementverwaltung mitzuteilen.Bezugspreise: Einzelheft 22,-€.Jahresabonnement Printausgabe 76,-€ (für Mitglieder der Dt.Gesellschaft für Osteuropakunde e. V. sowie für Studierende (gg.Nachweis) 57,-€

Bezugszeit: Das Abonnement gilt zunchst fr ein Jahr; es verlngert sich, wenn nicht drei Monate vor Ablauf dieses Jahres schriftlich gekndigt wird. Darber hinaus sind Kndigungen jeweils drei Monate vor Jahresende der Abonnementverwaltung mitzuteilen. Bezugspreise: Einzelheft 22,-. Jahresabonnement Printausgabe 76,- (fr Mitglieder der Dt. Gesellschaft fr Osteuropakunde e. V. sowie fr Studierende (gg. Nachweis) 57,-

Bezugszeit: Das Abonnement gilt zunchst fr ein Jahr; es verlngert sich, wenn nicht drei Monate vor Ablauf dieses Jahres schriftlich gekndigt wird. Darber hinaus sind Kndigungen jeweils drei Monate vor Jahresende der Abonnementverwaltung mitzuteilen. Bezugspreise: Einzelheft 22,-. Jahresabonnement Printausgabe 76,- (fr Mitglieder der Dt. Gesellschaft fr Osteuropakunde e. V. sowie fr Studierende (gg. Nachweis) 57,-

We study three same spin state fermions of mass M interacting with a distinguishable particle of mass m in the unitary limit where the interaction has a zero range and an infinite s-wave scattering length. We predict an interval of mass ratio 13.384 < M/m < 13.607 where there exists a purely four-body Efimov effect, leading to the occurrence of weakly bound tetramers without Efimov trimers.

We report on shot noise measurements in carbon nanotube based Fabry-Perot electronic interferometers. As a consequence of quantum interferences, the noise power spectral density oscillates as a function of the voltage applied to the gate electrode. The quantum shot noise theory accounts for the data quantitatively. It allows to confirm the existence of two nearly degenerate orbitals. At resonance, the transmission of the nanotube approaches unity, and the nanotube becomes noiseless, as observed in quantum point contacts. In this weak backscattering regime, the dependence of the noise on the backscattering current is found weaker than expected, pointing either to electron-electron interactions or to weak decoherence.

We investigate the appearance of spontaneous coherence in the parametric emission from planar semiconductor microcavities in the strong coupling regime. Calculations are performed by means of a Quantum Monte Carlo technique based on the Wigner representation of the coupled exciton and cavity-photon fields. The numerical results are interpreted in terms of a non-equilibrium phase transition occurring at the parametric oscillation threshold: below the threshold, the signal emission is incoherent, and both the first and the second-order coherence functions have a finite correlation length which becomes macroscopic as the threshold is approached. Above the threshold, the emission is instead phase-coherent over the whole two-dimensional sample and intensity fluctuations are suppressed. Similar calculations for quasi-one-dimensional microcavities show that in this case the phase-coherence of the signal emission has a finite extension even above the threshold, while intensity fluctuations are suppressed.

Gordon Gong is a research assistant professor in the Osteoporosis Research Center, Department of Internal Medicine, Creighton University School of Medicine, Omaha, NE. Contact author: [email protected]. The author wishes to thank Judith Kissel, PhD, Cathie Schmit, RN, MSN, and Shirley Meiyer, LPA, for reviewing and editing this manuscript. This publication was supported by a Nebraska Tobacco Settlement Biomedical Research Development Grant (LB692) awarded to Creighton University by the State of Nebraska, but its content is solely the result of the author’s work and does not necessarily represent the official views of that state.