RSS 1.0Physics and Astronomy publications (MU)
Items in this collection are the scholarly output of the Department of Physics and Astronomy faculty, staff, and students, either alone or as co-authors, and which may or may not have been published in an alternate format. Items may contain more than one file type.
Items in MOspace are protected by copyright, with all rights reserved, unless otherwise indicated.
Recent Submissions
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Spin accumulation from interlayer scattering in semiconductor bilayers
(arXiv, 2011-02)Electrons in double-layer semiconductor heterostructures experience two types of spin- orbit interaction: one arises within each layer from the lack of bulk inversion symmetry and/or externally applied electric fields; the ... -
Drude weight, plasmon dispersion, and a.c. conductivity in doped graphene sheets
(arXiv, 2011-01)We demonstrate that the plasmon frequency and Drude weight of the electron liquid in a doped graphene sheet are strongly renormalized by electron-electron interactions even in the long-wavelength limit. This e ffect is ... -
Spin Drag in Ultracold Fermi Mixtures with Repulsive Interactions
(arXiv, 2010-12)We calculate the spin-drag relaxation rate for a two-component ultracold atomic Fermi gas with positive scattering length between the two spin components. In one dimension we find that it vanishes linearly with temperature. ... -
D'yakonov-Perel' spin relaxation for degenerate electrons in the electron-hole liquid
(arXiv, 2010-10)We present an analytical study of the D'yakonov-Perel' spin relaxation time for degenerate electrons in a photo-excited electron-hole liquid in intrinsic semiconductors exhibiting a spin-split band structure. The ... -
Plasmon mass and Drude weight in strongly spin-orbit-coupled 2D electron gases
(arXiv, 2010-10)Spin-orbit-coupled two-dimensional electron gases (2DEGs) are a textbook example of helical Fermi liquids, i.e. quantum liquids in which spin (or pseudospin) and momentum degrees-of-freedom at the Fermi surface have a ... -
Viscous corrections to the resistance of nano-junctions: a dispersion relation approach
(arXiv, 2011-01)It is well known that the viscosity of a homogeneous electron liquid diverges in the limits of zero frequency and zero temperature. A nanojunction breaks translational invariance and necessarily cuts off this divergence. ... -
The quantum mechanics of electric conduction in crystals
(American Association of Physics Teachers, 2010-09)We introduce a model of electrons incident on a one-dimensional periodic potential and show that conduction is a result of the interference of different parts of an electron wave that bounce multiple times through a series ... -
Response properties of III-V dilute magnetic semiconductors: interplay of disorder, dynamical electron-electron interactions and band-structure effects
(arXiv, 2011-01)A theory of the electronic response in spin and charge disordered media is developed with the particular aim to describe III-V dilute magnetic semiconductors like GaMnAs. The theory combines a detailed k.p description of ... -
Localized diffusive motion on two different time scales in solid alkane nanoparticles
(Institute of Physics, 2010-10)High-energy-resolution quasielastic neutron scattering on three complementary spectrometers has been used to investigate molecular diffusive motion in solid nano- to bulk-sized particles of the alkane n-C32H66. The ... -
Molecular Hydrogen in the Ring Nebula: Clumpy Photodissociation Regions
(University of Chicago Press, 2003-02)We present a 0 .65 resolution H2 1-0 S(1) 2.122 mm image of the Ring Nebula (NGC 6720), which was taken with the Near Infrared Imager at the WIYN 3.5 m telescope on Kitt Peak. The high resolution of the H2 observation is ... -
The Dust Ring of Luminous Blue Variable Candidate HD 168625: Infrared Observations and Model Calculations
(Institute of Physics, 2003-12)We present a 2.218 lm image from the Hubble Space Telescope/Near Infrared Camera and Multi-Object Spectrometer (NICMOS) and a 55 lm image from ISOPHOT of the dust ring surrounding the luminous blue variable (LBV) candidate ... -
Processing of Presolar Grains around Post-Asymptotic Giant Branch Stars: Silicon Carbide as the Carrier of the 21 Micron Feature
(Institute of Physics, 2004-01)Some proto-planetary nebulae (PPNs) exhibit an enigmatic feature in their infrared spectra at ~21 μm. This feature is not seen in the spectra of either the precursors to PPNs, the asymptotic giant branch (AGB) stars, or ... -
The Multitude of Molecular Hydrogen Knots in the Helix Nebula
(Institute of Physics, 2005-10)We present Hubble Space Telescope NICMOS imaging of the H2 2.12 μm emission in five fields in the Helix Nebula ranging in radial distance from 250'' to 450'' from the central star. The images reveal arcuate structures with ... -
The Nature and Origin of Molecular Knots in Planetary Nebulae
(American Institute of Physics, 2005-11)Planetary Nebulae (PNe) are major contributors to the enrichment of the interstellar medium (ISM). Knots and filaments in the ionized gas images of PNe are common, if not ubiquitous. Additionally, it has been shown that ... -
The 10 μm Feature of M-Type Stars in the Large Magellanic Cloud and the Dust Condensation Sequence
(American Astronomical Society, 2005-11)We present 7-14 mm Infrared Space Observatory (ISO) spectroscopy of 12 M-type evolved stars in the Large Magellanic Cloud (LMC), in order to study the dust mineralogy and condensation process around these stars. The sample ... -
The Effect of Stellar Evolution on SiC Dust Grain Sizes
(American Astronomical Society, 2005-11)Stars on the asymptotic giant branch (AGB) produce dust in their circumstellar shells. The nature of the dust-forming environment is influenced by the evolution of the stars, in terms of both chemistry and density, leading ... -
Astromineralogy of the 13 μm Feature in the Spectra of Oxygen-rich Asymptotic Giant Branch Stars. I. Corundum and Spinel
(American Astronomical Society, 2006-04)Asymptotic giant branch (AGB) stars have several interesting infrared spectral features. Approximately half the oxygen-rich AGB stars to be investigated spectroscopically exhibit a feature at ~13 μm. The carrier of this ... -
Massive-Star Supernovae as Major Dust Factories
(arXiv, 2006-06)We present late-time optical and mid-infrared observations of the Type-II supernova 2003gd in NGC 628. Mid-infrared excesses consistent with cooling dust in the ejecta are observed 499-678 days after outburst, and are ... -
The mass-loss return from evolved stars to the Large Magellanic Cloud. III. Dust properties for carbon-rich asymptotic giant branch stars
(EDP Sciences, 2010-11)We present a radiative transfer model for the circumstellar dust shell around a Large Magellanic Cloud (LMC) long-period variable (LPV) previously studied as part of the Optical Gravitational Lensing Experiment (OGLE) ... -
The SAGE-Spec Spitzer Legacy program: The life-cycle of dust and gas in the Large Magellanic Cloud: Point source classification I.
(arXiv, 2010-09)We present the classification of 197 point sources observed with the Infrared Spectrograph in the SAGE-Spec Legacy program on the Spitzer Space Telescope. We introduce a decision-tree method of object classification based ...