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Your search keyword '"Moshegov, N. T."' showing total 45 results
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45 results on '"Moshegov, N. T."'

1. Quantum Hall Effect induced by electron-electron interaction in disordered GaAs layers with 3D spectrum

Author

Murzin, S. S., Claus, I., Jansen, A. G. M., Moshegov, N. T., Toropov, A. I., and Eberl, K.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

It is shown that the observed Quantum Hall Effect in epitaxial layers of heavily doped n-type GaAs with thickness (50-140 nm) larger the mean free path of the conduction electrons (15-30 nm) and, therefore, with a three-dimensional single-particle spectrum is induced by the electron-electron interaction. The Hall resistance R_xy of the thinnest sample reveals a wide plateau at small activation energy E_a=0.4 K found in the temperature dependence of the transverse resistance R_xx. The different minima in the transverse conductance G_xx of the different samples show a universal temperature dependence (logarithmic in a large range of rescaled temperatures T/T_0) which is reminiscent of electron-electron-interaction effects in coherent diffusive transport., Comment: 6 pages, 3 figures, 1 table

Published
1998
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2. 2D Lattice of coupled Sinai billiards: metal or insulator at g<<1

Author

Budantsev, M. V., Kvon, Z. D., Pogosov, A. G., Gusev, G. M., Portal, J. C., Maude, D. K., Moshegov, N. T., and Toropov, A. I.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Disordered Systems and Neural Networks
Abstract

We investigate the transport in a two-dimensional (2D) lattice of coupled Sinai billiards fabricated on the basis of a high-mobility 2D electron gas in GaAs/AlGaAs heterojunction. For the states with low reduced conductivity g<<1 an anomalously weak temperature dependence of g was found. The large negative magnetoresistance described by the Lorentz line-shape of the width corresponding to the half magnetic flux quantum through the area of the billiard is observed. In going from g>1 to g<<1 it strongly increases. The Shubnikov-de Haas oscillations and commensurability magnetoresistance peak are preserved at g<<1. The data suggest that the system studied behaves more like a metal than an insulator at g<<1 and is not described by the generally accepted picture of Anderson localization., Comment: 8 pages, 3 figures. Submitted to Phys. Rev. Lett

Published
1998

12. Fourier-transform infrared and Raman spectroscopies of plasmon anisotropy in heavily doped GaAs/AlAs superlattices.

Author

Pusep, Yu. A., Silva, M. T. O., Galzerani, J. C., Milekhin, A. G., Moshegov, N. T., and Toropov, A. I.

Subjects
PLASMONS (Physics), GALLIUM, ARSENIC, ALUMINUM, SUPERLATTICES
Abstract

Presents information on a study which analyzed the plasmon-longitudinal optical phonon vibrational modes in heavily doped gallium arsenic (As)/aluminum As superlattices. Experimental procedure; Results and discussion; Conclusion.

Published
1996
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13. Raman Study of the Topology of InAs/GaAs Self-Assembled Quantum Dots

Author

UNIVERSIDADE FEDERAL DE SAO CARLOS (BRAZIL), Zanelatto, G., Pusep, Y. A., Moshegov, N. T., Toropov, A. I., Basmaji, P., UNIVERSIDADE FEDERAL DE SAO CARLOS (BRAZIL), Zanelatto, G., Pusep, Y. A., Moshegov, N. T., Toropov, A. I., and Basmaji, P.

Abstract

The topology of self assembled InAs/GaAs quantum dots was studied by resonant Raman scattering caused by the interface modes localized near the edges of the dots. Evidences were found that on both sides of the InAs layer containing the dots. their topologies show some resemblances. In addition. in the multilayered systems the evidence of the coalescence of the dots (which form vertical columns) in neighbor layers separated by the distance smaller than 25 monolayers was obtained., Pres: 7th Int Symp Nanostructures: Physics and Technology, St Petersburg, Russia. 14-18 Jun 1999. p70-73. This article is from ADA407055 Nanostructures: Physics and Technology. 7th International Symposium. St. Petersburg, Russia, June 14-18, 1999 Proceedings

Published
1999

35. RAMAN SCATTERING IN GaAs-InAS SUPERLATTICES.

Author

Haisler, V. A., Govorov, A. O., Kurochkina, T. V., Moshegov, N. T., Stenin, S. I., Toropov, A. I., and Shebanin, A. P.

Subjects
SUPERLATTICES, RAMAN scattering, GALLIUM arsenide, VIBRATION (Mechanics), DISPERSION (Chemistry)
Published
1990

38. Study of Strain Relaxation in InAs/GaAs Strained-layer Superlattices by Raman Spectroscopy and Electron Microscopy

Author

Gutakovsky, A. K., Pintus, S. M., Toropov, A. I ., Moshegov, N. T., Haisler, V. A., Rubanov, S., and Munroe, P.

Abstract

InAs/GaAs strained-layer superlattices (SLS) grown on a GaAs(100) substrate were studied by both Raman spectroscopy (RS) and transmission electron microscopy (TEM). It was shown that the interfaces inside the superlattice are coherent, but the superlattice&endash;substrate interface contain an orthogonal two-dimensional network of 60&deg; misfit dislocations. Using these experimental data values of elastic strain in individual layers and the average values of the residual elastic strain in SLS were determined. The latter are approximately one order of magnitude higher than theoretically predicted data, which suggests that the relaxation of elastic strains was not fully complete. Subsequent annealing of these structures led to the generation of more misfit dislocations, consistent with further relaxation of elastic strain.

Published
2001

43. Lasing characteristics of lasers with a vertical cavity based on In[sub 0.2]Ga[sub 0.8]As quantum wells.

Author

Gaısler, V. A., Toropov, A. I., Bakarov, A. K., Kalagin, A. K., Moshegov, N. T., Ténné, D. A., Kachanova, M. M., Kopp, O. R., Nenasheva, L. A., and Medvedev, A. S.

Subjects
SEMICONDUCTOR lasers, GALLIUM arsenide semiconductors
Abstract

Semiconductor lasers with a vertical cavity with a high external quantum efficiency and high radiation power have been developed and constructed. Powers up to 10 W at T=300 K and 20 W at T= 250 K have been obtained for 500 µm aperture lasers operating in the pulsed regime. [ABSTRACT FROM AUTHOR]

Published
1999
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