Browsing by Keywords "Phonons"
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Anharmonicity in GaTe layered crystals
(WileyVCH Verlag GmbH & Co. KGaA, 2002)The temperature dependencies (10300 K) of seven Ramanactive mode frequencies in layered semiconductor gallium telluride have been measured in the frequency range from 25 to 300 cm 1. Softening and broadening of the ... 
Anharmonicity of zonecenter optical phonons: Raman scattering spectra of GaSe0.5S0.5 layered crystal
(IOPscience, 2002)The temperature dependencies (10300 K) of the eight Ramanactive mode frequencies and linewidths in GaSe0.5S0.5 layered crystal have been measured in the frequency range from 10 to 320 cm1. We observed softening and ... 
Confined optical phonon effects on the band gap renormalization in quantum wire structures
(Elsevier Science, 1999)We consider the different approximations for the bandgap renormalization (BGR) within the random phase approximation (RPA), the quasistatic limit and the plasmonpole approximation, and compare with the full result. We ... 
Correlation of TEM data with confined phonons to determine strain and size of Ge nanocrystals embedded in SixNy matrix
(Academic Press, 2017)Models that use phonon confinement fail to provide consistent results for nanocrystal sizes in differing dielectric matrices due to varying stress experienced by nanocrystals in different dielectric environments. In cases ... 
Dynamical screening effects in hotelectron scattering from electronhole plasma and LOphonon modes in quantum wires
(Elsevier, 1996)We present a fully dynamical and finite temperature study of the hotelectron momentum relaxation rate and the power loss in a coupled system of electronhole plasma and bulk LOphonons in a quantum wire structure. ... 
Effects of anisotropy on the critical temperature in layered nonadiabatic superconductors
(Elsevier Science B.V., 2003)The generalized anisotropic Eliashberg theory is employed to study the critical temperature of layered nonadiabatic superconductors where the relevant phonon energy is comparable to the Fermi energy. We consider a ... 
Energy and mass of 3D and 2D polarons in the overall range of the electronphonon coupling strength
(Institute of Physics Publishing Ltd., 1994)The groundstate characterization of the polaron problem is retrieved within the framework of a variational scheme proposed previously by Devreese et al for the bound polaron. The formulation is based on the standard ... 
Energy relaxation probed by weak antilocalization measurements in GaN heterostructures
(2009)Energy relaxation and electronphonon (ep) interaction are investigated in wurtzite Al0.15Ga0.85 N/AlN/GaN and Al0.83 In0.17 N/AlN/GaN heterostructures with polarization induced twodimensional electron gases in the ... 
Existence of a metallic phase in a 1D HolsteinHubbard model at half filling
(Elsevier B.V., 2007)The onedimensional halffilled HolsteinHubbard model is studied using a series of canonical transformations including phonon coherence effect that partly depends on the electron density and is partly independent and also ... 
First Principles Study of Barium Chalcogenides
(2008)In this study, ab initio calculation results of the vibrational properties and elastic parameters as well as characteristic Debye temperature and Poisson's ratios of two barium chalcogenides, BaSe and BaS, which crystallize ... 
Formation of Ge nanocrystals and SiGe in PECVD grown SiNx: Ge thin films
(Elsevier, 2006)Formation of Ge nanocrystals in SiNx matrices has been studied using plasma enhanced chemical vapor deposition in both as deposited samples as well as in postvacuum annealed samples. Low temperature and short duration ... 
HartreeFock approximation of bipolaron state in quantum dots and wires
(Springer, 2010)The bipolaronic ground state of two electrons in a spherical quantum dot or a quantum wire with parabolic boundaries is studied in the strong electronphonon coupling regime. We introduce a variational wave function that ... 
Highenergy electron relaxation and fullband electron dynamics in aluminium nitride
(Elsevier Science B.V., 2002)Material properties of AlN, particularly its wide band gap around 6 eV, warrant its operation in the highfield transport regimes reaching MV/cm fields. In this theoretical work, we examine the fullband scattering of ... 
Hybrid plasmonphonon polariton bands in graphenehexagonal boron nitride metamaterials [Invited]
(Optical Society of America, 2017)We theoretically investigate midinfrared electromagnetic wave propagation in multilayered graphenehexagonal boron nitride (hBN) metamaterials. Hexagonal boron nitride is a natural hyperbolic material that supports highly ... 
Hydrodynamic approach for modelling transport in quantum well device structures
(Institute of Physics Publishing Ltd., 1998)A semiclassical approach for modelling electron transport in quantum well structures is presented. The model is based on the balance equations governing the conservation of particle density, momentum and energy with Monte ... 
Isotope Effect and Phonon Softening in Superconducting Borocarbides and Boronitrides
(1998)The isotope effect in the recently disvovered class o superconductors LuNi2B2C and La3Ni2B2N3 is investigated in the context of electronsquezed phonon interaction renormalizing the Nid electronelectron correlations. ... 
Lattice dynamics and elastic properties of lanthanum monopnictides
(2008)In this study, first principles calculation results of the second order elastic constants and lattice dynamics of two lanthanum monopnictides, LaN and LaBi, which crystallize in rocksalt structure (B1 phase), are presented. ... 
Localpair superconductivity in very high magnetic fields
(Scientific and Technical Research Council of Turkey  TUBITAK,Turkiye Bilimsel ve Teknik Arastirma Kurumu, 1996)Superconductivity of narrowband systems with local, shortrange attractive interaction in very high magnetic fields is discussed. By examining the excitation spectra of both typeII superconductors with BCS like interaction ... 
Lowtemperature phase transitions in TlGaS2 layer crystals
(Pergamon Press, 1993)Polarized Raman scattering spectra of TlGaS2 layer crystals have been studied for the first time as a function of temperature between 8.5 and 295 K. No evidence for a soft mode behaviour has been found. The anomalies ... 
Magnetic field effects on an electron near an impenetrable dielectric surface
(1996)The interaction of an extrinsic electron with the surface optical modes of a semiinfinite medium is retrieved under the effect of a weak magnetic field. It is observed that for an electron in a bound state near the surface, ...