8,427 research outputs found
Effect of Dzyaloshinskii Moriya interaction on magnetic vortex
The effect of the Dzyaloshinskii Moriya interaction on the vortex in magnetic
microdisk was investigated by micro magnetic simulation based on the Landau
Lifshitz Gilbert equation. Our results show that the DM interaction modifies
the size of the vortex core, and also induces an out of plane magnetization
component at the edge and inside the disk. The DM interaction can destabilizes
one vortex handedness, generate a bias field to the vortex core and couple the
vortex polarity and chirality. This DM-interaction-induced coupling can
therefore provide a new way to control vortex polarity and chirality
Magnetization reversal in Kagome artificial spin ice studied by first-order reversal curves
Magnetization reversal of interconnected Kagome artificial spin ice was
studied by the first-order reversal curve (FORC) technique based on the
magneto-optical Kerr effect and magnetoresistance measurements. The
magnetization reversal exhibits a distinct six-fold symmetry with the external
field orientation. When the field is parallel to one of the nano-bar branches,
the domain nucleation/propagation and annihilation processes sensitively depend
on the field cycling history and the maximum field applied. When the field is
nearly perpendicular to one of the branches, the FORC measurement reveals the
magnetic interaction between the Dirac strings and orthogonal branches during
the magnetization reversal process. Our results demonstrate that the FORC
approach provides a comprehensive framework for understanding the magnetic
interaction in the magnetization reversal processes of spin-frustrated systems
Holographic interacting dark energy in the braneworld cosmology
We investigate a model of brane cosmology to find a unified description of
the radiation-matter-dark energy universe. It is of the interacting holographic
dark energy with a bulk-holographic matter . This is a five-dimensional
cold dark matter, which plays a role of radiation on the brane. Using the
effective equations of state instead of the
native equations of state , we show that this model
cannot accommodate any transition from the dark energy with to the phantom regime . Furthermore, the case of interaction between cold dark matter and
five dimensional cold dark matter is considered for completeness. Here we find
that the redshift of matter-radiation equality is the same order
as . Finally, we obtain
a general decay rate which is suitable for describing all interactions
including the interaction between holographic dark energy and cold dark matter.Comment: 17 pages, 4 figure
Discovery From Non-Parties (Third-Party Discovery) in International Arbitration
International arbitration rules and many arbitration laws usually provide procedures that permit tribunals to order parties to disclose documents and other materials to the other parties.1 More complex are the rules that determine opportunities to obtain discovery from persons that are not party to the arbitration (third-party discovery). This article will review third-party discovery under the Federal Arbitration Act (FAA) and the provisions of the US Code s.1782 that authorise US courts to act in aid of actions before foreign tribunals. Section 1782 has unique interest at this time because it figured prominently in the EU antitrust investigation of Intel that was initiated on request from Advanced Micro Devices (AMD). Early in that investigation, AMD filed a s.1782 request in the US District Court to obtain evidence from US sources for submission to the DG-Competition of the European Commission (EC). This request ultimately led to the Supreme Court’s decision in Intel Corp v Advanced Micro Devices Inc2 which appeared to significantly expand the scope of s.1782. Ironically, after AMD won on key legal issues in the Supreme Court, the District Court on remand exercised its discretion and denied the request for judicial assistance. This paper first describes the FAA non-party discovery rules and the split among the federal appellate courts concerning the authority of arbitrators to order prehearing discovery from non-parties. Next, it provides an analysis of the meaning of the terms “interested party” and “tribunal”—terms that were controversially interpreted by the Supreme Court in Intel and are essential to the application of s.1782. Finally, it discusses the “discretionary” factors used by the federal courts in deciding whether to grant a s.1782 request even when the statutory criteria are met. The opportunity to exercise this discretion seems to rebut the argument that the Supreme Court’s interpretation of s.1782 gives participants before foreign tribunals more discovery rights in the United States than are available to the parties in arbitrations covered by the FAA
Limits on Radio Continuum Emission from a Sample of Candidate Contracting Starless Cores
We used the NRAO Very Large Array to search for 3.6 cm continuum emission
from embedded protostars in a sample of 8 nearby ``starless'' cores that show
spectroscopic evidence for infalling motions in molecular emission lines. We
detect a total of 13 compact sources in the eight observed fields to 5 sigma
limiting flux levels of typically 0.09 mJy. None of these sources lie within 1'
of the central positions of the cores, and they are all likely background
objects. Based on an extrapolation of the empirical correlation between the
bolometric luminosity and 3.6 cm luminosity for the youngest protostars, these
null-detections place upper limits of ~0.1 L_sun (d/140pc)^2 on the
luminosities of protostellar sources embedded within these cores. These limits,
together with the extended nature of the inward motions inferred from molecular
line mapping (Lee et al. 2001), are inconsistent with the inside-out collapse
model of singular isothermal spheres and suggest a less centrally condensed
phase of core evolution during the earliest stages of star formation.Comment: Accepted to the Astronomical Journal; 12 pages, 1 figur
Anisotropic s-wave superconductivity in MgB_2
It has recently been observed that MgB_2 is a superconductor with a high
transition temperature. Here we propose a model of anisotropic s-wave
superconductivity which consistently describes the observed properties of this
compound, including the thermodynamic and optical response in sintered MgB_2
wires. We also determine the shape of the quasiparticle density of states and
the anisotropy of the upper critical field and the superfluid density which
should be detectable once single-crystal samples become available.Comment: RevTex, 10 pages with 4 eps figure
Transport and the Order Parameter of Superconducting SrRuO
Recent experiments make it appear more likely that the order parameter of the
unconventional superconductor SrRuO has a spin-triplet -wave
symmetry. We study ultrasonic absorption and thermal conductivity of
superconducting SrRuO and fit to the recent data for various -wave
candidates. It is shown that only -wave symmetry can account
qualitatively for the transport data.Comment: 4 pages, 2 figures, references added and update
Schr\"{o}dinger Fields on the Plane with non-Abelian Chern-Simons Interactions
Physical content of the nonrelativistic quantum field theory with non-Abelian
Chern-Simons interactions is clarified with the help of the equivalent first-
quantized description which we derive in any physical gauge.Comment: 12 pages, LaTex, SNUTP 94-1
A Spectral Line Survey from 138.3 to 150.7 GHZ toward Orion-KL
We present the results of a spectral line survey from 138.3 to 150.7 GHz
toward Orion-KL. The observations were made using the 14 m radio telescope of
Taeduk Radio Astronomy Observatory. Typical system temperatures were between
500 and 700 K, with the sensitivity between K in units of .
A total of 149 line spectra are detected in this survey. Fifty lines have
been previously reported, however we find 99 new detections. Among these new
lines, 32 are `unidentified', while 67 are from molecular transitions with
known identifications. There is no detection of H or He recombination lines.
The identified spectra are from a total of 16 molecular species and their
isotopic variants. In the range from 138.3 to 150.7 GHz, the strongest spectral
line is the J=3-2 transition of CS molecule, followed by transitions of the
, , , and . Spectral lines from
the large organic molecules such as , , , and are prominent; with 80 % of the
identified lines arising from transitions of these molecules. The rotational
temperatures and column densities are derived using the standard rotation
diagram analysis for (), , and with and . These estimates are fairly comparable to the values for the
same molecule in other frequency regions by other studies.Comment: 10 figures, 2 tex files for a manuscript and tables, accepted to Ap
Combined potential and spin impurity scattering in cuprates
We present a theory of combined nonmagnetic and magnetic impurity scattering
in anisotropic superconductors accounting for the momentum-dependent impurity
potential. Applying the model to the d-wave superconducting state, we obtain a
quantitative agreement with the initial suppression of the critical temperature
due to Zn and Ni substitutions as well as electron irradiation defects in the
cuprates. We suggest, that the unequal pair-breaking effect of Zn and Ni may be
related to a different nature of the magnetic moments induced by these
impurities.Comment: 5 pages, 3 tables, RevTex, to be published in Phys. Rev.
- …