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Full-Text Articles in Physical Sciences and Mathematics
Electronic Structure Properties And Bcs Superconductivity In Ss-Pyrochlore Oxides: KoSS₂O₆, Rolando Saniz, Julia E. Medvedeva, Lin Hui Ye, Tatsuya Shishidou, Arthur J. Freeman
Electronic Structure Properties And Bcs Superconductivity In Ss-Pyrochlore Oxides: KoSS₂O₆, Rolando Saniz, Julia E. Medvedeva, Lin Hui Ye, Tatsuya Shishidou, Arthur J. Freeman
Physics Faculty Research & Creative Works
We report a first-principles density-functional calculation of the electronic structure and properties of the recently discovered superconducting β-pyrochlore oxide KOs2O6. We find that the electronic structure near the Fermi energy EF is dominated by strongly hybridized Os 5d and O 2p states. A van Hove singularity very close to Ef leads to a relatively large density of states at EF, and the Fermi surface exhibits strong nesting along several directions. These features could provide the scattering processes leading to the observed anomalous temperature dependence of the resistivity and to the rather large …
Statistics Of Transmission In One-Dimensional Disordered Systems: Universal Characteristics Of States In The Fluctuation Tails, Lev I. Deych, Mikhail V. Erementchouk, Alexander A. Lisyansky, Alexey Yamilov, Hui Cao
Statistics Of Transmission In One-Dimensional Disordered Systems: Universal Characteristics Of States In The Fluctuation Tails, Lev I. Deych, Mikhail V. Erementchouk, Alexander A. Lisyansky, Alexey Yamilov, Hui Cao
Physics Faculty Research & Creative Works
We numerically study the distribution function of the conductance (transmission) in the one-dimensional tight-binding Anderson and periodic-on-average superlattice models in the region of fluctuation states where single parameter scaling is not valid. We show that the scaling properties of the distribution function depend upon the relation between the system's length L and the length ls determined by the integral density of states. For long enough systems, L ≫ ls, the distribution can still be described within a new scaling approach based upon the ratio of the localization length lloc and ls. In an intermediate …
Density Of Resonant States And A Manifestation Of Photonic Band Structure In Small Clusters Of Spherical Particles, Alexey Yamilov, Hui Cao
Density Of Resonant States And A Manifestation Of Photonic Band Structure In Small Clusters Of Spherical Particles, Alexey Yamilov, Hui Cao
Physics Faculty Research & Creative Works
We introduce a numerical recipe for calculating the density of the resonant states of the clusters of dielectric spheres. Using truncated multipole expansions (generalized multisphere Mie solution) we obtain the scattering matrix of the problem. By introducing an infinitesimal absorption in the spheres we express the dwell time of the electromagnetic wave in terms of the elements of the scattering matrix. Using the parameters in recent light localization experiments [Phys. Rev. Lett. 87, 153901 (2001)], we demonstrate that the density of the resonant states, related to the dwell time, shows the formation of the photonic band structure in small clusters …
Local Polariton Modes And Resonant Tunneling Of Electromagnetic Waves Through Periodic Bragg Multiple Quantum Well Structures, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky
Local Polariton Modes And Resonant Tunneling Of Electromagnetic Waves Through Periodic Bragg Multiple Quantum Well Structures, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky
Physics Faculty Research & Creative Works
We study analytically defect polariton states in Bragg multiple quantum well structures and defect-induced changes in transmission and reflection spectra. Defect layers can differ from the host layers in three ways: exciton-light coupling strength, exciton resonance frequency, and interwell spacing. We show that a single defect leads to two local polariton modes in the photonic band gap. These modes cause peculiarities in reflection and transmission spectra. Each type of defect can be reproduced experimentally, and we show that each of these plays a distinct role in the optical properties of the system. For some defects, we predict a narrow transmission …
Concept Of Local Polaritons And Optical Properties Of Mixed Polar Crystals, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky
Concept Of Local Polaritons And Optical Properties Of Mixed Polar Crystals, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky
Physics Faculty Research & Creative Works
The concept of local polaritons is used to describe the optical properties of mixed crystals in the frequency region of their restrahlen band. It is shown that this concept allows for a physically transparent explanation of the presence of weak features in the spectra of so-called one-mode crystals and for one-two mode behavior. The previous models Were able to explain these features only with the use of many fitting parameters. We show that under certain Conditions new impurity-induced polariton modes may arise within the restrahlen of the host crystals, and study their dispersion laws and density of states. Particularly, we …