scholarly journals TYPICAL-MEDIUM THEORY OF MOTT–ANDERSON LOCALIZATION

2010 ◽  
Vol 24 (12n13) ◽  
pp. 1680-1726 ◽  
Author(s):  
V. Dobrosavljević
Keyword(s):  
Order Parameter ◽  
Lattice Site ◽  
Fundamental Problem ◽  
Metal Insulator ◽  
Medium Theory ◽  
Anderson Transition ◽  
Dynamical Order ◽  
Static Order ◽  
Two Fluid ◽  
Insight Into

The Mott and the Anderson routes to localization have long been recognized as the two basic processes that can drive the metal–insulator transition (MIT). Theories separately describing each of these mechanisms were discussed long ago, but an accepted approach that can include both has remained elusive. The lack of any obvious static symmetry distinguishing the metal from the insulator poses another fundamental problem, since an appropriate static order parameter cannot be easily found. More recent work, however, has revisited the original arguments of Anderson and Mott, which stressed that the key diference between the metal end the insulator lies in the dynamics of the electron. This physical picture has suggested that the "typical" (geometrically averaged) escape rate [Formula: see text] from a given lattice site should be regarded as the proper dynamical order parameter for the MIT, one that can naturally describe both the Anderson and the Mott mechanism for localization. This article provides an overview of the recent results obtained from the corresponding Typical-Medium Theory, which provided new insight into the the two-fluid character of the Mott–Anderson transition.

A MODEL HIERARCHY FOR IONOSPHERIC PLASMA MODELING

2004 ◽  
Vol 14 (03) ◽  
pp. 393-415 ◽  
Author(s):  
CHRISTOPHE BESSE ◽  
PIERRE DEGOND ◽  
FABRICE DELUZET ◽  
JEAN CLAUDEL ◽  
GÉRARD GALLICE ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Plasma Density ◽  
Maxwell Equations ◽  
Ionospheric Plasma ◽  
Practical Interest ◽  
Plasma Modeling ◽  
Model Hierarchy ◽  
Great Practical Interest ◽  
Two Fluid ◽  
Insight Into

This paper deals with the modeling of the ionospheric plasma. Starting from the two-fluid Euler–Maxwell equations, we present two hierarchies of models. The MHD hierarchy deals with large plasma density situations while the dynamo hierarchy is adapted to lower density situations. Most of the models encompassed by the dynamo hierarchy are classical ones, but we shall give a unified presentation of them which brings a new insight into their interrelations. By contrast, the MHD hierarchy involves a new (at least to the authors) model, the massless-MHD model. This is a diffusion system for the density and magnetic field which could be of great practical interest. Both hierarchies terminate with the "classical" Striation model, which we shall investigate in detail.

scholarly journals Perception and misperception of surface opacity

2017 ◽  
Vol 114 (52) ◽  
pp. 13840-13845 ◽  
Author(s):  
Phillip J. Marlow ◽  
Juno Kim ◽  
Barton L. Anderson
Keyword(s):  
Visual System ◽  
Fundamental Problem ◽  
Surface Orientation ◽  
The Body ◽  
Local Surface ◽  
Significant Information ◽  
Scene Structure ◽  
The Relationship ◽  
Opaque Surface ◽  
Insight Into

A fundamental problem in extracting scene structure is distinguishing different physical sources of image structure. Light reflected by an opaque surface covaries with local surface orientation, whereas light transported through the body of a translucent material does not. This suggests the possibility that the visual system may use the covariation of local surface orientation and intensity as a cue to the opacity of surfaces. We tested this hypothesis by manipulating the contrast of luminance gradients and the surface geometries to which they belonged and assessed how these manipulations affected the perception of surface opacity/translucency. We show that (i) identical luminance gradients can appear either translucent or opaque depending on the relationship between luminance and perceived 3D surface orientation, (ii) illusory percepts of translucency can be induced by embedding opaque surfaces in diffuse light fields that eliminate the covariation between surface orientation and intensity, and (iii) illusory percepts of opacity can be generated when transparent materials are embedded in a light field that generates images where surface orientation and intensity covary. Our results provide insight into how the visual system distinguishes opaque surfaces and light-permeable materials and why discrepancies arise between the perception and physics of opacity and translucency. These results suggest that the most significant information used to compute the perceived opacity and translucency of surfaces arise at a level of representation where 3D shape is made explicit.

The Anderson transition

1975 ◽  
Vol 345 (1641) ◽  
pp. 169-205 ◽  
Keyword(s):  
Electrical Properties ◽  
Fermi Energy ◽  
Inversion Layer ◽  
Two Dimensional ◽  
Layer System ◽  
Metal Insulator Transition ◽  
Mobility Edge ◽  
Metal Insulator ◽  
Anderson Transition ◽  
Extended States

An outline is given of the electrical properties expected in a disordered solid or fluid which shows a metal-insulator transition of Anderson type. This is one in which the Fermi energy of the electrons passes through a mobility edge separating extended states from states localized by disorder, as the composition or some other parameter is changed. Some of the experimental evidence for this kind of transition is described. In particular, a relatively detailed account is given of the two dimensional inversion layer system in which the relevant parameters may be varied in a single device by direct electrical means.

RADIATION DAMAGE EFFECTS ON TRANSPORT AND COLOSSAL MAGNETORESISTANCE IN La(1-x)CaxMnO3

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3815-3819
Author(s):  
D. G. NAUGLE ◽  
K. D. D. RATHNAYAKA ◽  
B. I. BELEVTSEV
Keyword(s):  
Crystal Lattice ◽  
Electron Irradiation ◽  
Colossal Magnetoresistance ◽  
Ion Irradiation ◽  
Metal Insulator ◽  
Lattice Disorder ◽  
Small Lattice ◽  
Lattice Damage ◽  
Insight Into ◽  
Severe Disorder

The effects of crystal lattice disorder induced by irradiation of La-Ca-Mn-O films are reviewed. These experiments provide insight into the anomalous transport properties and colossal magnetoresistance (CMR) of these perovskites. Electron irradiation produces only slight lattice damage, about 10-5 displacements per atom (dpa) which would be imperceptible in an ordinary "bad" metal or activated semiconductor but gives large changes in resistance that illustrate the exotic nature of transport in both the metallic and insulating phases of the CMR films. Ion irradiation produces damage ranging from 5×10-3 dpa to 2.4×10-2 dpa which provides a systematic picture of CMR and transport from relatively small lattice disorder to more severe disorder, sufficient to completely supress the metal-insulator (M-I) transition.

scholarly journals Gain-Assisted Optical Pulling Force on Plasmonic Graded Nano-Shell with Equivalent Medium Theory

Physics ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 955-968
Author(s):  
Yamin Wu ◽  
Yang Huang ◽  
Pujuan Ma ◽  
Lei Gao
Keyword(s):  
Optical Force ◽  
Core Shell ◽  
Deep Insight ◽  
Medium Theory ◽  
Additional Degree ◽  
The Core ◽  
Matter Interaction ◽  
Light Matter Interaction ◽  
Pulling Force ◽  
Insight Into

The tunable optical pulling force on a graded plasmonic core-shell nanoparticle consisting of a gain dielectric core and graded plasmonic shell is investigated in the illumination of a plane wave. In this paper, the electrostatic polarizability and the equivalent permittivity of the core-shell sphere are derived and the plasmonic enhanced optical pulling force in the antibonding and bonding dipole modes of the graded nanoparticle are demonstrated. Additionally, the resonant pulling force occurring on the dipole mode is shown to be dependent on the aspect ratio of the core-shell particle, which is illustrated by the obtained equivalent permittivity. This shows that the gradation of the graded shell will influence the plasmonic feature of the particle, thus further shifting the resonant optical force peaks and strengthening the pulling force. The obtained results provide an additional degree of freedom to manipulate nanoparticles and give a deep insight into light–matter interaction.

scholarly journals Critical Behavior at the Mott-Anderson Transition: A Typical-Medium Theory Perspective

2009 ◽  
Vol 102 (15) ◽  
Author(s):  
M. C. O. Aguiar ◽  
V. Dobrosavljević ◽  
E. Abrahams ◽  
G. Kotliar
Keyword(s):  
Critical Behavior ◽  
Medium Theory ◽  
Anderson Transition

scholarly journals Simulation of the Collapse of an Underwater Explosion Bubble under a Circular Plate

2005 ◽  
Vol 12 (3) ◽  
pp. 217-225 ◽  
Author(s):  
Kit-Keung Kan ◽  
James H. Stuhmiller ◽  
Philemon C. Chan
Keyword(s):  
Hydraulic Jump ◽  
Underwater Explosion ◽  
Complex Interaction ◽  
Bubble Collapse ◽  
Toroidal Bubble ◽  
Jet Impact ◽  
Advection Term ◽  
Two Fluid ◽  
Insight Into ◽  
Good Agreement

A two-fluid, computational fluid dynamics study of the phenomena of bubble collapse under a submersed flat plate has been performed. In order to handle the rapidly changing bubble-water interface accurately, second order upwind differencing is used in calculating the advection term. Good agreement with experimental data is obtained for the pressure distribution on the plate. The computational results provide insight into the phenomenology of the jet impact, the formation of a radial hydraulic jump, and the complex interaction of that hydraulic jump with the collapsing toroidal bubble.

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