Microscopic theory of quasi one-dimensional conductors

2007 ◽  
pp. 71-76
Author(s):  
Günther Meissner
Keyword(s):  
Microscopic Theory ◽  
One Dimensional

scholarly journals On the Casimir energy of the electromagnetic field in the dispersive and absorptive medium

2014 ◽  
Vol 29 (18) ◽  
pp. 1450101
Author(s):  
M. A. Braun
Keyword(s):  
Dielectric Constant ◽  
Electromagnetic Field ◽  
Casimir Effect ◽  
Direct Interaction ◽  
Microscopic Theory ◽  
Casimir Energy ◽  
Indirect Interaction ◽  
One Dimensional ◽  
Absorptive Medium ◽  
The One

The microscopic theory of the Casimir effect in the dielectric is studied in the framework when absorption is realized via a reservoir modeled by a set of oscillators with continuously distributed frequencies with the aim to see if the effects depend on the form of interaction with the reservoir. A simple case of the one-dimensional dielectric between two metallic plates is considered. Two possible models are investigated, the direct interaction of the electromagnetic field with the reservoir and indirect interaction via an intermediate oscillator imitating the atom. It is found that with the same dielectric constant the Casimir effect is different in these two cases, which implies that in the second model it cannot be entirely expressed via the dielectric constant as in the well-known Lifshitz formula.

Sound Propagation in Cdw and Sdw

1989 ◽  
Vol 173 ◽  
Author(s):  
Attila Virosztek ◽  
Kazumi Maki
Keyword(s):  
Spin Density ◽  
Sound Propagation ◽  
Density Wave ◽  
Spin Density Wave ◽  
Diffusion Constant ◽  
Microscopic Theory ◽  
Present Theory ◽  
Phase Correlation ◽  
One Dimensional ◽  
Ideal Situation

ABSTRACTWe present a microscopic theory of the sound propagation in quasi one dimensional charge density wave (CDW), spin density wave (SDW) and field induced spin density wave (FISDW). First, we consider the ideal situation that the phase correlation length in the CDW or the SDW is infinite. In this limit due to the diffusion pole at iω = Dq2 in a variety of correlation functions the sound propagation depends on a) what is the ratio ω/Dq2 and b) if the CDW (or the SDW) is pinned or unpinned where D is the diffusion constant. Second, when the CDW (or the SDW) is unpinned, the phason starts to participate in the screening of the ionic potential. However, since the unpinned part is strongly inhomogeneous, the contribution of the phason term depends on the wave vector of q of the sound wave like (1 + (Lq)2)−1 where L is the Fukuyama-Lee-Rice coherence length. The present theory accounts for a variety of features observed in sound propagation in quasi-one dimensional CDW systems like NbSe3 and TaS3.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Intergrowth of modulated structures in high Tc Bi-Sr-Ca-Cu-O superconductors

1990 ◽  
Vol 48 (4) ◽  
pp. 76-77
Author(s):  
A.Q. He ◽  
G.W. Qiao ◽  
J. Zhu ◽  
H.Q. Ye
Keyword(s):  
Twin Structure ◽  
Modulated Structure ◽  
High Tc ◽  
One Dimensional ◽  
Lattice Constants ◽  
Superconducting Phases ◽  
Modulated Structures ◽  
Layer Structures

Since the first discovery of high Tc Bi-Sr-Ca-Cu-O superconductor by Maeda et al, many EM works have been done on it. The results show that the superconducting phases have a type of ordered layer structures similar to that in Y-Ba-Cu-O system formulated in Bi2Sr2Can−1CunO2n+4 (n=1,2,3) (simply called 22(n-1) phase) with lattice constants of a=0.358, b=0.382nm but the length of c being different according to the different value of n in the formulate. Unlike the twin structure observed in the Y-Ba-Cu-O system, there is an incommensurate modulated structure in the superconducting phases of Bi system superconductors. Modulated wavelengths of both 1.3 and 2.7 nm have been observed in the 2212 phase. This communication mainly presents the intergrowth of these two kinds of one-dimensional modulated structures in 2212 phase.

Sign in / Sign up

Export Citation Format

Share Document