10,431 research outputs found
Novel ordering of an S = 1/2 quasi one-dimensional Ising-like anitiferromagnet in magnetic field
High-field specific heat measurements on BaCo2V2O8, which is a good
realization of an S = 1/2 quasi one-dimensional Ising-like antifferomagnet,
have been performed in magnetic fields up to 12 T along the chain and at
temperature down to 200 mK. We have found a new magnetic ordered state in the
field-induced phase above Hc ~ 3.9 T. We suggest that a novel type of the
incommensurate order, which has no correspondence to the classical spin system,
is realized in the field-induced phase.Comment: 4pages, 4figure
The binary black-hole problem at the third post-Newtonian approximation in the orbital motion: Static part
Post-Newtonian expansions of the Brill-Lindquist and Misner-Lindquist
solutions of the time-symmetric two-black-hole initial value problem are
derived. The static Hamiltonians related to the expanded solutions, after
identifying the bare masses in both solutions, are found to differ from each
other at the third post-Newtonian approximation. By shifting the position
variables of the black holes the post-Newtonian expansions of the three metrics
can be made to coincide up to the fifth post-Newtonian order resulting in
identical static Hamiltonians up the third post-Newtonian approximation. The
calculations shed light on previously performed binary point-mass calculations
at the third post-Newtonian approximation.Comment: LaTeX, 9 pages, to be submitted to Physical Review
Longitudinal SDW order in a quasi-1D Ising-like quantum antiferromagnet
From neutron diffraction measurements on a quasi-1D Ising-like Co
spin compound BaCoVO, we observed an appearance
of a novel type of incommensurate ordering in magnetic fields. This ordering is
essentially different from the N{\' e}el-type ordering, which is expected for
the classical system, and is caused by quantum fluctuation inherent in the
quantum spin chain. A Tomonaga-Luttinger liquid (TLL) nature characteristic of
the gapless quantum 1D system is responsible for the realization of the
incommensurate ordering.Comment: 4pages, 4figur
On Time-dependent Collapsing Branes and Fuzzy Odd-dimensional Spheres
We study the time-dependent dynamics of a collection of N
collapsing/expanding D0-branes in type IIA String Theory. We show that the
fuzzy-S^3 and S^5 provide time-dependent solutions to the Matrix Model of
D0-branes and its DBI generalisation. Some intriguing cancellations in the
calculation of the non-abelian DBI Matrix actions result in the fuzzy-S^3 and
S^5 having the same dynamics at large-N. For the Matrix model, we find analytic
solutions describing the time-dependent radius, in terms of Jacobi elliptic
functions. Investigation of the physical properties of these configurations
shows that there are no bounces for the trajectory of the collapse at large-N.
We also write down a set of useful identities for fuzzy-S^3, fuzzy-S^5 and
general fuzzy odd-spheres.Comment: 35 pages, latex; v2: discussion in Appendix B on the large-N limit of
the associator is modified, main results of paper unchange
Management of localized energy in discrete nonlinear transmission lines
The manipulation of locked intrinsic localized modes/discrete breathers is
studied experimentally in nonlinear electric transmission line arrays.
Introducing a static lattice impurity in the form of a capacitor, resistor or
inductor has been used both to seed or destroy and attract or repel these
localized excitations. In a nonlinear di-element array counter propagating
short electrical pulses traveling in the acoustic branch are used to generate a
stationary intrinsic localized mode in the optic branch at any particular
lattice site. By changing the pulse polarity the same localized excitation can
be eliminated demonstrating that the dynamical impurity associated with the
propagating electrical pulse in the acoustic branch can trigger optical
localized mode behavior.Comment: submitte
Quantitative analysis of Sr2RuO4 ARPES spectra: Many-body interactions in a model Fermi liquid
ARPES spectra hold a wealth of information about the many-body interactions
in a correlated material. However, the quantitative analysis of ARPES spectra
to extract the various coupling parameters in a consistent manner is extremely
challenging, even for a model Fermi liquid system. We propose a fitting
procedure which allows quantitative access to the intrinsic lineshape,
deconvolved of energy and momentum resolution effects, of the correlated
2-dimensional material Sr2RuO4. For the first time in correlated 2-dimensional
materials, we find an ARPES linewidth that is narrower than its binding energy,
a key property of quasiparticles within Fermi liquid theory. We also find that
when the electron-electron scattering component is separated from the
electron-phonon and impurity scattering terms it decreases with a functional
form compatible with Fermi liquid theory as the Fermi energy is approached. In
combination with the previously determined Fermi surface, these results give
the first complete picture of a Fermi liquid system via ARPES. Furthermore, we
show that the magnitude of the extracted imaginary part of the self-energy is
in remarkable agreement with DC transport measurements.Comment: 10 pages, 5 figure
Formation of finite antiferromagnetic clusters and the effect of electronic phase separation in Pr{_0.5}Ca{_0.5}Mn{_0.975}Al{_0.025}O{_3}
We report the first experimental evidence of a magnetic phase arising due to
the thermal blocking of antiferromagnetic clusters in the weakened charge and
orbital ordered system Pr{_0.5}Ca{_0.5}Mn{_0.975}Al{_0.025}O{_3}. The third
order susceptibility (\chi_3) is used to differentiate this transition from a
spin or cluster glass like freezing mechanism. These clusters are found to be
mesoscopic and robust to electronic phase separation which only enriches the
antiphase domain walls with holes at the cost of the bulk, without changing the
size of these clusters. This implies that Al substitution provides sufficient
disorder to quench the length scales of the striped phases.Comment: 4 Post Script Figure
A reliability-based approach for influence maximization using the evidence theory
The influence maximization is the problem of finding a set of social network
users, called influencers, that can trigger a large cascade of propagation.
Influencers are very beneficial to make a marketing campaign goes viral through
social networks for example. In this paper, we propose an influence measure
that combines many influence indicators. Besides, we consider the reliability
of each influence indicator and we present a distance-based process that allows
to estimate the reliability of each indicator. The proposed measure is defined
under the framework of the theory of belief functions. Furthermore, the
reliability-based influence measure is used with an influence maximization
model to select a set of users that are able to maximize the influence in the
network. Finally, we present a set of experiments on a dataset collected from
Twitter. These experiments show the performance of the proposed solution in
detecting social influencers with good quality.Comment: 14 pages, 8 figures, DaWak 2017 conferenc
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