Electric field and effective dielectric constant in random media with non-linear response

Abstract. Observations by the EISCAT Svalbard radar show that electron temperatures Te in the cusp electrojet reach up to about 4000 K. The heat is tapped and converted from plasma convection in the near Earth space by a Pedersen current that is carried by electrons due to the presence of irregularities and their demagnetising effect. The heat is transfered to the neutral gas by collisions. In order to enhance Te to such high temperatures the maximally possible dissipation at 50% demagnetisation must nearly be reached. The effective Pedersen conductances are found to be enhanced by up to 60% compared to classical values. Conductivities and conductances respond significantly to variations of the electric field strength E, and "Ohm's law" for the ionosphere becomes non-linear for large E.

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Electric-Field Dependence of the Effective Dielectric Constant in Graphene

Nano Letters ◽

10.1021/nl303611v ◽

2013 ◽

Vol 13 (3) ◽

pp. 898-902 ◽

Cited By ~ 123

Author(s):

Elton J. G. Santos ◽

Efthimios Kaxiras

Keyword(s):

Dielectric Constant ◽

Electric Field ◽

Field Dependence ◽

Effective Dielectric Constant ◽

Electric Field Dependence

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The refractive indices of calcite and aragonite

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1924.0026 ◽

1924 ◽

Vol 105 (732) ◽

pp. 370-386 ◽

Cited By ~ 67

Keyword(s):

Dielectric Constant ◽

Electric Field ◽

Wave Train ◽

Relative Displacement ◽

Effective Dielectric Constant ◽

Refractive Indices ◽

Double Refraction ◽

Isotropic Media ◽

Cubic System ◽

The Moment

1. The two crystalline forms of calcium carbonate, calcite and aragonite, have been analyzed by X-ray methods, and they both display strong double refraction. It is therefore of interest to see whether the large difference in the refractive indices for light polarized in different planes can be explained by the atomic arrangements in the crystals. The electron theory of dielectric media supposes that the atoms of the medium become polarized under the influence of an external electric field. The positive and negative components of the atom suffer a relative displacement, which is equivalent to the development of an electric doublet placed at or near the centre of the atom. The moment of the doublet is proportional to the strength of the electric field in its immediate neighbourhood, the constant of proportionality being characteristic of the atom considered. The local field which causes the polarization of the atom may for convenience be divided into two parts, the first being the force arising from charges in the field, including the doublets of the polarized medium not in the immediate neighbourhood of the atom, the second being the force arising from the doublets in its immediate neighbourhood. In isotropic media, such as liquids or amorphous solids, the average effect of the neighbouring doublets will be same what-ever the direction of the electric field which causes polarization. In Crystals of lower symmetry than that of the cubic system, this will not be the case. The influence of the neighbouring doublets on an atom will depend on the orientation of the electric field with reference to the crystal axes; this will be the case both for the alternating fields of a wave train as well as for a steady field. The effective dielectric constant will therefore depend upon the direction of the electric vector of the waves, and since the velocity of light is inversely proportional to the square root of the dielectric constant, the crystal will display double refraction.

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Linear and non-linear response of stepped metal surfaces to a static electric field

Surface Science ◽

10.1016/0039-6028(93)90020-k ◽

1993 ◽

Vol 297 (1) ◽

pp. 106-111 ◽

Cited By ~ 8

Author(s):

H. Ishida ◽

A. Liebsch

Keyword(s):

Electric Field ◽

Linear Response ◽

Metal Surfaces ◽

Static Electric Field ◽

Non Linear

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On the non-linear response of piezoelectric slabs under weak electric fields: Experimental and analytical modelling

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/09544062jmes975 ◽

2009 ◽

Vol 223 (6) ◽

pp. 1493-1506

Author(s):

M K Samal ◽

P Seshu

Keyword(s):

Electric Field ◽

Electric Fields ◽

Linear Response ◽

Perturbation Technique ◽

Ritz Method ◽

Response Spectra ◽

Near Resonance ◽

Non Linear ◽

Linear Material

Piezoceramic materials exhibit different types of non-linearities depending on the magnitude of the mechanical and electric field strength in the piezoelectric continuum. Some of the non-linearities observed under weak electric fields are the presence of superharmonics in the response spectra, jump phenomena, and so on, especially if the system is excited near resonance. In this article, an analytical solution (in the two-dimensional plane stress domain) for the non-linear response of a rectangular piezoceramic slab has been obtained by the use of Rayleigh—Ritz method and perturbation technique. The eigenfunction obtained from the solution of differential equations of the linear problem has been used as the shape function in the Rayleigh—Ritz method. Forced vibration experiments have been conducted on rectangular piezoceramic slabs of two different materials (e.g. PIC 181 and PIC 255) by applying varying electric field strengths across the thickness, and the displacement and current responses have been measured. Experiments have also been conducted for the first two free in-plane modes in the case of the piezoceramic PIC 181. Analytical solutions have been obtained by using the current formulations and they are found to compare well with those of the experiment. These solutions should serve as a method to validate the finite-element formulations as well as to help in the determination of non-linear material property coefficients for these materials.

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A bistatic measurement technique for characterization of the effective dielectric constant of random media using a monostatic radar

Proceedings of the 1996 IEEE National Radar Conference ◽

10.1109/nrc.1996.510676 ◽

2002 ◽

Author(s):

A. Nashashibi ◽

K. Sarabandi

Keyword(s):

Dielectric Constant ◽

Measurement Technique ◽

Random Media ◽

Effective Dielectric Constant

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Enhancement of Electric Field inside Metallodielectric Metamaterial

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.11-12.117 ◽

2006 ◽

Vol 11-12 ◽

pp. 117-120

Author(s):

Won Woo Cho ◽

G. Zouganelis ◽

Hitoshi Ohsato

Keyword(s):

Dielectric Constant ◽

Finite Difference ◽

Electric Field ◽

Time Domain ◽

Finite Difference Time Domain ◽

Near Field ◽

Effective Dielectric Constant ◽

Incident Electric Field ◽

Metal Wires ◽

Difference Time

A metallodielectric metamaterial have been investigated by using FDTD (Finite Difference Time Domain) method and fabricated with a resin based rapid prototyping machine. It was composed of 7 layers of parallel periodic copper wires embedded in resin. The metallodielectric metamaterial shows a different near field distribution with direction of incident electric field E that causes different electromagnetic (EM) properties. In particular, when incident electric field E is vertical to the wires inside resin, we observe enhacement of electric field in the vicinity of the embedded metal wires according to the incident direction of electirc field E as compared with dielectirc wihout metal wires. The enhanced electric field by the embedded metal wire is responsible for the enhancement of effective dielectric constant.

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