1,525 research outputs found
Neutrino Oscillations with the MINOS, MINOS+, T2K, and NOvA Experiments
This paper discusses recent results and near-term prospects of the
long-baseline neutrino experiments MINOS, MINOS+, T2K and NOvA. The non-zero
value of the third neutrino mixing angle {\theta}13 allows experimental
analysis in a manner which explicitly exhibits appearance and disappearance
dependencies on additional parameters associated with mass-hierarchy, CP
violation, and any non-maximal {\theta}23. These current and near-future
experiments begin the era of precision accelerator long-baseline measurements
and lay the framework within which future experimental results will be
interpreted.Comment: 41 pages, 36 figures, submitted to New Journal of Physic
Order-disorder oscillations in exciton-polariton superfluids
The dynamics of an exciton-polariton superfluid resonantly pumped in a
semiconductor microcavity are investigated by mean-field theory. Modulational
instability develops into crystalline order and then ordered and disordered
states alternately form. A supersolid-like state is also found, in which
superflow coexists with crystalline order at rest.Comment: 5 pages, 3 figures, 6 movie
Anisotropic s-wave superconductivity in single crystals CaAlSi from penetration depth measurements
In- and out-of-plane London penetration depths were measured in single
crystals CaAlSi (T_{c}=6.2 K and 7.3 K) using a tunnel-diode resonator. A full
3D BCS analysis of the superfluid density is consistent with a prolate
spheroidal gap, with a weak-coupling BCS value in the ab-plane and stronger
coupling along the c-axis. The gap anisotropy was found to significantly
decrease for higher T_{c} samples.Comment: 4 page
Critical phase of a magnetic hard hexagon model on triangular lattice
We introduce a magnetic hard hexagon model with two-body restrictions for
configurations of hard hexagons and investigate its critical behavior by using
Monte Carlo simulations and a finite size scaling method for discreate values
of activity. It turns out that the restrictions bring about a critical phase
which the usual hard hexagon model does not have. An upper and a lower critical
value of the discrete activity for the critical phase of the newly proposed
model are estimated as 4 and 6, respectively.Comment: 11 pages, 8 Postscript figures, uses revtex.st
MHD Simulation of The Inner Galaxy with Radiative Cooling and Heating
We investigate the role of magnetic field on the gas dynamics in the Galactic
bulge region by three dimensional simulations with radiative cooling and
heating. While high-temperature corona with is formed in the
halo regions, the temperature near the Galactic plane is following the thermal equilibrium curve determined by the radiative cooling
and heating. Although the thermal energy of the interstellar gas is lost by
radiative cooling, the saturation level of the magnetic field strength does not
significantly depend on the radiative cooling and heating. The magnetic field
strength is amplified to on average, and reaches several
hundred locally. We find the formation of magnetically dominated
regions at mid-latitudes in the case with the radiative cooling and heating,
which is not seen in the case without radiative effect. The vertical thickness
of the mid-latitude regions is at the radial location of
from the Galactic center, which is comparable to the
observed vertical distribution of neutral atomic gas. When we take the average
of different components of energy density integrated over the Galactic bulge
region, the magnetic energy is comparable to the thermal energy. We conclude
that the magnetic field plays a substantial role in controlling the dynamical
and thermal properties of the Galactic bulge region.Comment: Submitted to ApJ; 21 pages, 18 figures 3 tables. Comment are welcom
Evidence for field-induced excitations in low-temperature thermal conductivity of Bi_2Sr_2CaCu_2O_8
The thermal conductivity ,, of Bi_2Sr_2CaCu_2O_8 was studied as a
function of magnetic field. Above 5 K, after an initial decrease,
presents a kink followed by a plateau, as recently reported by Krishana et al..
By contrast, below 1K, the thermal conductivity was found to \emph{increase}
with increasing field. This behavior is indicative of a finite density of
states and is not compatible with the existence of a field-induced fully gapped
state which was recently proposed to describe the
plateau regime. Our low-temperature results are in agreement with recent works
predicting a field-induced enhancement of thermal conductivity by Doppler shift
of quasi-particle spectrum.Comment: 4 pages including 4 eps figures, submitted to Phys. Rev. Let
Noiseless Collective Motion out of Noisy Chaos
We consider the effect of microscopic external noise on the collective motion
of a globally coupled map in fully desynchronized states. Without the external
noise a macroscopic variable shows high-dimensional chaos distinguishable from
random motion. With the increase of external noise intensity, the collective
motion is successively simplified. The number of effective degrees of freedom
in the collective motion is found to decrease as with the
external noise variance . It is shown how the microscopic noise can
suppress the number of degrees of freedom at a macroscopic level.Comment: 9 pages RevTex file and 4 postscript figure
Density matrix renormalization group for the Berezinskii-Kosterlitz-Thouless transition of the 19-vertex model
We embody the density matrix renormalization group (DMRG) method for the
19-vertex model on a square lattice in order to investigate the
Berezinskii-Kosterlitz-Thouless transition. Elements of the transfer matrix of
the 19-vertex model are classified in terms of the total value of arrows in one
layer of the square lattice. By using this classification, we succeed to reduce
enormously the dimension of the matrix which has to be diagonalized in the DMRG
method. We apply our method to the 19-vertex model with the interaction
and obtain for the conformal anomaly. PACS. 05.90.+m,
02.70.-cComment: RevTeX style, 20 pages, 12 figure
Energetics of Forced Thermal Ratchet
Molecular motors are known to have the high efficiency of energy
transformation in the presence of thermal fluctuation.
Motivated by the surprising fact, recent studies of thermal ratchet models
are showing how and when work should be extracted from non-equilibrium
fluctuations.
One of the important finding was brought by Magnasco where he studied the
temperature dependence on the fluctuation-induced current in a ratchet
(multistable) system and showed that the current can generically be maximized
in a finite temperature.
The interesting finding has been interpreted that thermal fluctuation is not
harmful for the fluctuation-induced work and even facilitates its efficiency.
We show, however, this interpretation turns out to be incorrect as soon as we
go into the realm of the energetics
[Sekimoto,J.Phys.Soc.Jpn.66,1234-1237(1997)]: the efficiency of energy
transformation is not maximized at finite temperature, even in the same system
that Magnasco considered. The maximum efficiency is realized in the absence of
thermal fluctuation. The result presents an open problem whether thermal
fluctuation could facilitate the efficiency of energetic transformation from
force-fluctuation into work.Comment: 3pages, 4sets of figure
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