The influence of the dynamic Jahn-Teller effect on the phonon-scattering mechanism at acceptors in semiconductors with cubic symmetry

Phonon scattering experiments of various types in cubic semiconductors doped with deep effective mass acceptors indicate an extra resonance scattering at some meV. It is shown, using Green's function and transformation techniques that these resonances are due to a dynamic Jahn-Teller effect of the 8 acceptor ground state.Phononen-Streuexperimente verschiedener Art weisen in kubischen, mit tiefen Effektivmassen-Akzeptoren dotierten Halbleitern eine zusätzliche Resonanzstreuung bei einigen meV auf. Es wird mit Hilfe von Greenschen Funktionen und Transformationsmethoden gezeigt, daß diese Resonanzen durch einen dynamischen Jahn-Teller-Effekt des 8-Akzeptorgroundzustandes hervorgerufen werden

Localized states in anthrylpolyenes : influence of geometry

Combining group theoretical arguments and (extended) Hückel calculations, it is shown that terminally anthryl-substituted polyenes exhibit states almost completely localized at the substituents. These localized states are related to characteristic optical transitions in anthracene which also are observed in anthrylpolyenes independent of the length of the polyene chain

2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.

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2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.

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withdrawn 2017 hrs ehra ecas aphrs solaece expert consensus statement on catheter and surgical ablation of atrial fibrillation

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Phonon scattering at acceptors with gamma8 ground states in semiconductors

The ground state of acceptors in cubic semiconductors is fourfold degenerate and the interaction with the lattice vibrations leads to the possibility of a Jahn-Teller effect, causing a dynamical splitting of the electronic levels. However, due to the extended nature of the wave function of the defect, random internal fields may have dominant influence to destroy the J.T. effect. Such an influence should be smaller for deeper acceptors, where the wavefunctions are more concentrated

Are zombie firms really contagious?

We test the hypotheses that zombie firms are less productive and have lower employment growth and lower gross investment ratios than non-zombie firms in the same industry sector and that they are a source of contagion for the latter. Ever since Caballero et al. (2008), it has been taken for granted that zombie firms cause contagion in non-zombie firms that ultimately leads to a misallocation of resources. Based on a yearly sample of around 8,000 firms that are observed between 2008 and 2018, we estimate the total factor productivity with the most common methods for the Cobb-Douglas and the translog production function that go beyond the Solow residual approach with fixed elasticities. We use four zombie firm definitions based on subsidized loans and the interest coverage ratio. As expected, we find that non-zombie firms are more productive, have a higher log employment growth and a higher gross investment ratio. However, we do not find any economically significant zombie firm contagion effects in non-zombie firms

g-tensor analysis of S- and Se- centers in cubic crystals

Experimental results for the electron spin resonance of the S− and Se− centers in alkali halide crystals are analysed and a theoretical model for their description is established. Most of the experimental results can be explained by assuming a strong T-t Jahn-Teller effect in the ground-state system combined with a spin-orbit coupling of similar strength. In particular, the principal g-tensor values, which are of importance for comparison with experiment are derived. They show good agreement with the measured data