50,358 research outputs found
Universality class of the restricted solid-on-solid model with hopping
We study the restricted solid-on-solid (RSOS) model with finite hopping
distance , using both analytical and numerical methods. Analytically, we
use the hard-core bosonic field theory developed by the authors [Phys. Rev. E
{\bf 62}, 7642 (2000)] and derive the Villain-Lai-Das Sarma (VLD) equation for
the case which corresponds to the conserved RSOS (CRSOS) model
and the Kardar-Parisi-Zhang (KPZ) equation for all finite values of .
Consequently, we find that the CRSOS model belongs to the VLD universality
class and the RSOS models with any finite hopping distance belong to the KPZ
universality class. There is no phase transition at a certain finite hopping
distance contrary to the previous result. We confirm the analytic results using
the Monte Carlo simulations for several values of the finite hopping distance.Comment: 13 pages, 3 figure
Anisotropy in magnetic and transport properties of Fe1-xCoxSb2
Anisotropic magnetic and electronic transport measurements were carried out
on large single crystals of Fe1-xCoxSb2 (0<= x <=1). The semiconducting state
of FeSb2 evolves into metallic and weakly ferromagnetic by substitution of Fe
with Co for x<0.5. Further doping induces structural transformation from
orthorhombic Pnnm structure of FeSb2 to monoclinic P21/c structure of CoSb2
where semiconducting and diamagnetic ground state is restored again. Large
magnetoresistance and anisotropy in electronic transport were observed.Comment: 7 pages, 6 figure
Derivation of continuum stochastic equations for discrete growth models
We present a formalism to derive the stochastic differential equations (SDEs)
for several solid-on-solid growth models. Our formalism begins with a mapping
of the microscopic dynamics of growth models onto the particle systems with
reactions and diffusion. We then write the master equations for these
corresponding particle systems and find the SDEs for the particle densities.
Finally, by connecting the particle densities with the growth heights, we
derive the SDEs for the height variables. Applying this formalism to discrete
growth models, we find the Edwards-Wilkinson equation for the symmetric
body-centered solid-on-solid (BCSOS) model, the Kardar-Parisi-Zhang equation
for the asymmetric BCSOS model and the generalized restricted solid-on-solid
(RSOS) model, and the Villain--Lai--Das Sarma equation for the conserved RSOS
model. In addition to the consistent forms of equations for growth models, we
also obtain the coefficients associated with the SDEs.Comment: 5 pages, no figur
A predictive standard model for heavy electron systems
We propose a predictive standard model for heavy electron systems based on a
detailed phenomenological two-fluid description of existing experimental data.
It leads to a new phase diagram that replaces the Doniach picture, describes
the emergent anomalous scaling behavior of the heavy electron (Kondo) liquid
measured below the lattice coherence temperature, T*, seen by many different
experimental probes, that marks the onset of collective hybridization, and
enables one to obtain important information on quantum criticality and the
superconducting/antiferromagnetic states at low temperatures. Because T* is
~J^2\rho/2, the nearest neighbor RKKY interaction, a knowledge of the
single-ion Kondo coupling, J, to the background conduction electron density of
states, \rho, makes it possible to predict Kondo liquid behavior, and to
estimate its maximum superconducting transition temperature in both existing
and newly discovered heavy electron families.Comment: 4 pages, 2 figures, submitted to J. Phys.: Conf. Ser. for SCES 201
Evidence of metallic clustering in annealed Ga1-xMnxAs from atypical scaling behavior of the anomalous Hall coefficient
We report on the anomalous Hall coefficient and longitudinal resistivity
scaling relationships on a series of annealed Ga1-xMnxAs epilayers (x~0.055).
As-grown samples exhibit scaling parameter n of ~ 1. Near the optimal annealing
temperature, we find n ~ 2 to be consistent with recent theories on the
intrinsic origins of anomalous Hall Effect in Ga1-xMnxAs. For annealing
temperatures far above the optimum, we note n > 3, similar behavior to certain
inhomogeneous systems. This observation of atypical behavior agrees well with
characteristic features attributable to spherical resonance from metallic
inclusions from optical spectroscopy measurements.Comment: 3 pages, 3 figure
Interplay between carrier and impurity concentrations in annealed GaMnAs intrinsic anomalous Hall Effect
Investigating the scaling behavior of annealed GaMnAs anomalous
Hall coefficients, we note a universal crossover regime where the scaling
behavior changes from quadratic to linear, attributed to the anomalous Hall
Effect intrinsic and extrinsic origins, respectively. Furthermore, measured
anomalous Hall conductivities when properly scaled by carrier concentration
remain constant, equal to theoretically predicated values, spanning nearly a
decade in conductivity as well as over 100 K in T. Both the qualitative
and quantitative agreement confirms the validity of new equations of motion
including the Berry phase contributions as well as tunablility of the intrinsic
anomalous Hall Effect.Comment: 4 pages, 5 figure
Pure spinor computation towards open string three-loop
Using the recent results in the pure spinor formulation, we lay out a
ground-work towards the full momentum space amplitudes of open superstrings at
three-loop. After briefly reviewing the one-loop amplitude, we directly work
out the two-loop and reproduce the result that was obtained by a symmetry
argument. For the three-loop, first we use the two-loop regulator as a warm-up
exercise. The result vanishes. We then employ the regulator that has been
recently proposed by Aisaka and Berkovits (AB). It is noted that the terms in
higher power in that render the two-loop
regulator disqualified for the three-loop do not contribute. This with a few
other indications suggests a possibility that the AB regulator might also lead
to a vanishing result. Nevertheless, we argue that it is possible to acquire
the three-loop amplitude, and present a result that we anticipate to be the
three-loop amplitude.Comment: 41 pages, latex, cosmetic change
Momentum-Resolved Electronic Structure of the High- Superconductor Parent Compound BaBiO
We investigate the band structure of BaBiO, an insulating parent
compound of doped high- superconductors, using \emph{in situ}
angle-resolved photoemission spectroscopy on thin films. The data compare
favorably overall with density functional theory calculations within the local
density approximation, demonstrating that electron correlations are weak. The
bands exhibit Brillouin zone folding consistent with known BiO breathing
distortions. Though the distortions are often thought to coincide with
Bi/Bi charge ordering, core level spectra show that bismuth is
monovalent. We further demonstrate that the bands closest to the Fermi level
are primarily oxygen derived, while the bismuth states mostly contribute
to dispersive bands at deeper binding energy. The results support a model of
Bi-O charge transfer in which hole pairs are localized on combinations of the O
orbitals.Comment: minor changes to text and other figures; includes link to online
Supplemental Material; accepted to Phys. Rev. Let
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