67 research outputs found
Commercialization of university innovative developments: a retrospective analysis of theoretical approaches to research
This study discusses a brief summary of a retrospective content analysis of scientific literature related to the commercialization of university scientists innovative development
Reflection Symmetry and Quantized Hall Resistivity near Quantum Hall Transition
We present a direct numerical evidence for reflection symmetry of
longitudinal resistivity and quantized Hall resistivity
near the transition between quantum Hall state and insulator, in accord
with the recent experiments. Our results show that a universal scaling behavior
of conductances, and , in the transition regime
decide the reflection symmetry of and quantization of ,
independent of particle-hole symmetry. We also find that in insulating phase
away from the transition region deviates from the quantization and
diverges with .Comment: 3 pages, 4 figures; figure 4 is replace
Estimation of Innovative Activity of the University
On the basis of Belgorod region innovation activity analysis, positive relationship between shipped innovation items and domestic research and development costs was found. Semantic differential was used for multiple estimation of BelSU innovation activity and competiveness. BelSU integrated index showed high-enough innovation activity of this universityyesBelgorod State Universit
Virality of medical content in Russian social media
The work objective is to conduct a sociological study aimed at assessing validity (appropriateness) of the traditional characteristics and formation of a pool of specialized characteristics of the viral content, used in the promotion of health services by means of social media marketin
Instability of charge ordered states in doped antiferromagnets
We analyze the induced interactions between localized holes in weakly-doped
Heisenberg antiferromagnets due to the modification of the quantum zero point
spin wave energy; i.e. the analogue of the Casimir effect. We show that this
interaction is uniformly attractive and falls off as r^{-2 d+1} in d
dimensions. For ``stripes'', i.e parallel (d-1)-dimensional hypersurfaces of
localized holes, the interaction energy per unit hyperarea is attractive and
falls, generically, like r^{-d}. We argue that, in the absence of a long-range
Coulomb repulsion between holes, this interaction leads to an instability of
any charge-ordered state in the dilute doping limit.Comment: Revtex, 5 pages two-column format, 3 ps figures (epsf). Two
references added and some textual change
Fluctuation-Induced First Order Transition between the Quantum Hall Liquid and Insulator
We study the phase transition between the quantum Hall liquid state and the
insulating state within the framework of the Chern-Simons-Landau-Ginzburg
theory of the quantum Hall effect. For the transition induced by a background
periodic potential in the absence of disorder, the model is described by a
relativistic scalar field coupled to the Chern-Simons gauge field. For this
system, we show that the transition is of the first order, induced by the
fluctuations of the gauge field, rather than second order, with statistical
angle-dependent scaling exponent.Comment: 5 pages, REVTEX 3.0, two PostScript pictures appended, preprint
SU-ITP-94-
Development of superconducting correlation at low temperatures in the two-dimensional t-J model
The equal-time pairing correlation function of the two-dimensional t-J model
on a square lattice is studied using a high-temperature expansion method. The
sum of the pairing correlation, its spatial dependence, and the correlation
length are obtained as functions of temperature down to . By
comparison of single-particle contributions in the correlation functions, we
find an effective attractive interaction between quasi-particles in
-wave pairings. It is shown that d-wave correlation grows rapidly
at low temperatures for 0.5 < n < 0.9, with n being the electron density. The
temperature for this growth is roughly scaled by J/2. This is in sharp contrast
to the Hubbard model in a weak or intermediate coupling region, where there is
no numerical evidence of superconductivity.Comment: 4 pages, 5 figure
Phase Diagram of Integer Quantum Hall Effect
The phase diagram of integer quantum Hall effect is numerically determined in
the tight-binding model, which can account for overall features of recently
obtained experimental phase diagram. In particular, the quantum Hall plateaus
are terminated by two distinct insulating phases, characterized by the Hall
resistance with classic and quantized values, respectively, which is also in
good agreement with experiments.Comment: 4 pages, RevTex, 4 PostScript figures; one new figure is added; minor
modifications in the tex
Duality Near Quantum Hall Transitions
A recent experiment by Shahar et al, on the phase transitions between quantum
Hall states and the insulator, found that the current-voltage characteristics
in the two phases are related by symmetry. It was suggested in this work that
this is evidence for charge-flux duality near quantum Hall transitions. Here we
provide details of this analysis. (Appearances notwithstanding, this is a
theoretical paper.)Comment: 26 pages, Revtex 3.
Edge Dynamics in Quantum Hall Bilayers II: Exact Results with Disorder and Parallel Fields
We study edge dynamics in the presence of interlayer tunneling, parallel
magnetic field, and various types of disorder for two infinite sequences of
quantum Hall states in symmetric bilayers. These sequences begin with the 110
and 331 Halperin states and include their fractional descendants at lower
filling factors; the former is easily realized experimentally while the latter
is a candidate for the experimentally observed quantum Hall state at a total
filling factor of 1/2 in bilayers. We discuss the experimentally interesting
observables that involve just one chiral edge of the sample and the correlation
functions needed for computing them. We present several methods for obtaining
exact results in the presence of interactions and disorder which rely on the
chiral character of the system. Of particular interest are our results on the
331 state which suggest that a time-resolved measurement at the edge can be
used to discriminate between the 331 and Pfaffian scenarios for the observed
quantum Hall state at filling factor 1/2 in realistic double-layer systems.Comment: revtex+epsf; two-up postscript at
http://www.sns.ias.edu/~leonid/ntwoup.p
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