摘要:

AbstractQuantum oscillations of magnetoresistance and thermomagnetic power of AsxSb1−x(0 ≦x≦ 1) alloys in stationary magnetic fields up to 15 T at low temperatures (1.9 ≦ T ≦ 17 K) are investigated. In the alloys, withx≦ 0.3, the quantum oscillations of thermomagnetic power with a “giant” amplitude are observed. The peculiarities of the energy spectrum reconstruction are determined and the composition range in which a break of the hole necks occurs is defined. It is established that AsSb alloys are semimetals in which overlapping of the hole and electron terms in the first approximation increases linearly

ISSN:0370-1972    

DOI:10.1002/pssb.2221360244

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractA theoretical investigation is made of the collision‐induced instabilities associated with helicon wave propagation in (type‐I) semiconductor superlattices. The dispersion relation which presents a rich structure of collective excitations in the quasi 2‐dimensional systems is used to study the convective and absolute instabilities. Numerical solutions of the dispersion relation are performed including the effect of retardation. The theoretical results in the strong‐coupling limit clearly indicate the parabolic nature of the modes at small wave vectors and thus lend support to the prediction of Quinn and coworkers. The analytical diagnosis, however, leads to some paradoxial conclusions and hence keeps one in dilemma to characterize these modes precisely as h

ISSN:0370-1972    

DOI:10.1002/pssb.2221360245

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractFree‐carrier infrared absorption spectra in GaAs are calculated for carrier scattering on ionized impurities and phonons due to Coulomb, Fröhlich, and deformation potential interaction. Starting from the Kubo formula and applying the diagram technique the interactions of electrons with electrons, phonons, and ionized impurities are taken into account in the random phase approximation (RPA). The obtained absorption spectra exhibit coupled plasmon‐phonon peaks which collapse for vanishing electron‐LO phonon interaction. By taking into account only plasmon and screening effects of the electron gas the calculated absorption spectra show plasmon bands in the case of carrier‐ionized impurity scattering and both, a LO phonon emission edge and weak plasmon‐LO phonon combination peaks in the case of carrier‐LO phonon scattering. The scattering of electrons by acoustic phonons is not influenced by plasmons. The dependences of various carrier scattering mechanisms on frequency, temperature, and material parameters are determine

ISSN:0370-1972    

DOI:10.1002/pssb.2221360246

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractTwo‐level systems in disordered metals can contribute to the\documentclass{article}\pagestyle{empty}\begin{document}$ \sqrt T $\end{document}resistivity anomaly at low temperatures, by reducing the resistivity increment due to weak localization. A comparison is made with the generally larger effects expected from electron‐electron correlations, and with data for Mg‐Zn glassy m

ISSN:0370-1972    

DOI:10.1002/pssb.2221360247

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractOne‐particle wave functions suitable for calculating the quantum Hall conductivity are discussed with respect to their local density of states. The new electron configurations connected with the quantum Hall effect indicate a spatial structuring in form of a Wigner‐like crystal or liquid. The calculated diagonal resistivity shows definite peaks in dependence on the magnetic field, the values of which are in good agreement with experimental data. The relationship between the filling factor and a two‐particle Green function is disc

ISSN:0370-1972    

DOI:10.1002/pssb.2221360248

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221360201

出版商:WILEY‐VCH Verlag    

年代:1986

数据来源: WILEY