Eugene Kogan

Random-matrix-theory approach to the intensity distributions of waves propagating in a random medium

Statistical properties of coherent radiation propagating in a quasi-one-dimensional random medium are studied in the framework of random-matrix theory. Distribution functions for the total transmission coefficient and the angular transmission coefficient are obtained.

RKKY interaction in graphene

We consider RKKY interaction between two magnetic impurities in graphene. The consideration is based on the perturbation theory for the thermodynamic potential in the imaginary time representation. We analyze the symmetry of the RKKY interaction on the bipartite lattice at half filling. Our analytical calculation of the interaction is based on direct evaluation of real space spin susceptibility. We show in the Appendix, added to the published version, that the approach can be easily generalized to the case of finite temperature.

Wave scattering through classically chaotic cavities in the presence of absorption: An information-theoretic model

We propose an information-theoretic model for the transport of waves through a chaotic cavity in the presence of absorption. The entropy of the S-matrix statistical distribution is maximized, with the constraint =alphan: n is the dimensionality of S, and 0</=alpha</=1, alpha=0(1) meaning complete (no) absorption. For strong absorption our result agrees with a number of analytical calculations already given in the literature. In that limit, the distribution of the individual (angular) transmission and reflection coefficients becomes exponential (Rayleigh statistics), even for n=1. For n>>1 Rayleigh statistics is attained even with no absorption; here, we extend the study to alpha<1. The model is compared with random-matrix-theory numerical simulations: it describes the problem very well for strong absorption, but fails for moderate and weak absorptions. Thus, in the latter regime, some important physical constraint is missing in the construction of the model.

Measurement of the conductance distribution function at a quantum Hall transition.

We study experimentally the reproducible conductance fluctuations between the quantum Hall plateaus in the conductance of two-terminal submicrometer silicon MOSFET’s. For the dramatic fluctuations at the insulator-to-first-plateau transition we find a conductance distribution that is approximately uniform between zero and e 2 /h. We point out that this is consistent with the prediction of random S-matrix theory for a conductor with single-channel leads in a magnetic field. @S0163-1829~96!51948-X#

Raman scattering and electrical resistance of highly disordered graphene

Raman scattering (RS) spectra and current-voltage characteristics at room temperature were measured in six series of small samples fabricated by means of electron-beam lithography on the surface of a large size

Localization of Charge Carriers in Monolayer Graphene Gradually Disordered by Ion Irradiation

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Symmetry Classification of Energy Bands in Graphene and Silicene

industrial monolayer graphene film. Samples were irradiated by different doses of

CPA density of states and conductivity in a double-exchange system containing impurities

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Effect of annealing on Raman spectra of monolayer graphene samples gradually disordered by ion irradiation

ion beam up to

Energy bands in graphene: Comparison between the tight-binding model andab initiocalculations

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