Physics and Astronomy publications (MU): Recent submissions
Now showing items 41-60 of 560
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Electromagnetic wave propagation in periodic structures: Bloch wave solution of Maxwell's equations
(American Physical Society, 1990)We examine the propagation of electromagnetic waves in periodic dielectric structures by solving the vector Maxwell equations with the plane-wave method. Contrary to experimental reports, as well as results of scalar-wave ... -
Electronic structure of the CaF2/Si(111) interface
(American Physical Society, 1991)The electronic structure of the CaF2/Si(111) interface calculated within the local-density-functional theory with the linear muffin-tin orbitals method is presented. We examine the interface states for three different ... -
Electron states, magnetism, and the Verwey transition in magnetite
(American Physical Society, 1991)Using density-functional calculations, we examine the electronic structure of magnetite in the spinel crystal structure in order to gain insight into the nature of the Verwey transition. The calculated cohesive and magnetic ... -
Energetic stabilization of the Mizoguchi structure for magnetite by
(American Physical Society, 1993)In view of some issues raised recently about the electronic structure and the nature of electronic conduction in simple cubic CsSnBr3, we have carried out a self-consistent density-functional calculation of the electronic ... -
Energetic stabilization of the Mizoguchi structure for magnetite by band-structure effects
(American Physical Society, 1993)We show that the Mizoguchi structure is energetically stabilized over the Verwey structure for magnetite by electron hopping on the B sublattice. We use the one-band Cullen-Callen model Hamiltonian for the electronic band ... -
Verwey transition in magnetite: Mean‐field solution of the three‐band model
(American Institute of Physics, 1994)The nature of the Verwey transition in magnetite (FqO,) within a three-band spinless model Hamiltonian is examined. These bands, which arise from the minority-spin tZg orbitals on the Fe(B) sublattice, are occupied by half ... -
Electronic Structure of the Perovskite Oxides: La1-xCaxMnO3
(American Physical Society, 1996)The electronic structures of the perovskite oxides, LaMnO3 and CaMnO3, are studied using density-functional methods. Antiferromagnetic insulating (AFI) solutions are obtained for both compounds within the local-density ... -
Electron states and electron-phonon coupling in the BEDT-TTF-based organic superconductors
(American Physical Society, 1996)The electronic structure and the coupling of electrons to the vibrational modes of a single bis (ethylenedithio)-tetrathiafulvalene (BEDT-TTF) molecule, the building block of a class of organic superconductors, are studied ... -
Density‐functional studies of the electronic structure of the perovskite oxides: La1−xCaxMnO3
(American Institute of Physics, 1996)Using density‐functional methods, we study the electronic structures of the lanthanum‐based ''double‐exchange'' perovskite magnets. Antiferromagnetic insulating solutions are obtained for both the end members, LaMnO3 and ... -
Electronic Shell Structure and Relative Abundances of Cesium-Coated C60
(American Physical Society, 1996)The relative abundances of C60Cs(N), N≤500, determined from mass spectra measurements, are presented and explained in terms of the successive filling of the electronic shells by the cesium valence electrons. The motion of ... -
Electronic structure and thermoelectric properties of bismuth telluride and bismuth selenide
(Institute of Physics, 1997)The electronic structures of the two thermoelectric materials Bi2Te3 and Bi2Se3 are studied using density-functional theory with the spin-orbit interaction included. The electron states in the gap region and the chemical ... -
Possible suppression of canted spin order in the double-exchange lanthanum manganites
(American Physical Society, 1997)The existence of the canted (noncollinear) spin order in the double-exchange magnets is examined by solving a model Hamiltonian using a combination of the Hartree-Fock approximation and an exact diagonalization scheme using ... -
Dynamics of flux penetration and critical currents in type-II superconductors
(American Physical Society, 1997)We study the dynamics of flux penetration and vortex pinning in a type-II superconductor by numerical simulations with forces appropriate in the London regime. Straight vortex lines at zero temperature are studied in a ... -
Charge ordering via electron-electron interactions in the colossal-magnetoresistive manganites
(American Physical Society, 1997)The coupled magnetic and charge-order transition observed in the manganites of the type R1-xMxMnO3 near half filling (x≃1/2) is shown to be the result of the interplay between the double-exchange, superexchange, and the ... -
Dynamical Jahn-Teller effect, double exchange and the isotope shift in the manganites: a toy model
(Institute of Physics, 1998)A minimal model, consisting of a 4 4 Hamiltonian and pertaining to a single Mn-O-Mn bond in the manganites, is introduced and solved to elucidate the physics of the dynamical Jahn-Teller effect on the double-exchange ... -
Electronic structure and exchange interactions in the manganese-based pyrochlore oxides
(American Physical Society, 1998)We describe the ferromagnetism in the manganese pyrochlores, such as Tl2Mn2O7 and Sc2Mn2O7, in terms of the interplay between superexchange, Zener double exchange, and indirect exchange, the first being antiferromagnetic ... -
Jahn-Teller coupling and double exchange in the two-site Van Vleck-Kanamori model
(American Institute of Physics, 1999)The effect of the dynamical Jahn-Teller coupling on the Anderson-Hasegawa double exchange (DE) in the manganites is studied in a two-site model taking into account the double degeneracy of the eg orbitals and their coupling ... -
Mean-field theory of charge ordering and phase transitions in the colossal-magnetoresistive manganites
(Institute of Physics, 1999)We study phase transitions in the colossal-magnetoresistive manganites by using a mean-field theory both at zero and non-zero temperatures. Our Hamiltonian includes double-exchange, superexchange, and Hubbard terms with ... -
Cooperative Jahn-Teller Coupling in the Manganites
(American Physical Society, 2000)The cooperative Jahn-Teller coupling between the Mn eg electrons and the oxygen octahedral distortions in LaMnO3 is studied using ab initio density-functional calculations and tight-binding models. The linear and quadratic ... -
Kronig-Penney model with the tail-cancellation method
(American Association of Physics Teachers, 2001)The Kronig-Penney model of an electron moving in a periodic potential is solved by the so-called tail-cancellation method. The problem also serves as a simple illustration of the tail-cancellation method itself.