117,803 research outputs found
Andreev Edge State on Semi-Infinite Triangular Lattice: Detecting the Pairing Symmetry in Na_0.35CoO_2.yH_2O
We study the Andreev edge state on the semi-infinite triangular lattice with
different pairing symmetries and boundary topologies. We find a rich phase
diagram of zero energy Andreev edge states that is a unique fingerprint of each
of the possible pairing symmetries. We propose to pin down the pairing symmetry
in recently discovered Na_xCoO_2 material by the Fourier-transformed scanning
tunneling spectroscopy for the edge state. A surprisingly rich phase diagram is
found and explained by a general gauge argument and mapping to 1D tight-binding
model. Extensions of this work are discussed at the end.Comment: 4 pages, 1 table, 4 figure
New high fill-factor triangular micro-lens array fabrication method using UV proximity printing
A simple and effective method to fabricate a high fill-factor triangular
microlens array using the proximity printing in lithography process is
reported. The technology utilizes the UV proximity printing by controlling a
printing gap between the mask and substrate. The designed approximate triangle
microlens array pattern can be fabricated the high fill-factor triangular
microlens array in photoresist. It is due to the UV light diffraction to
deflect away from the aperture edges and produce a certain exposure in
photoresist material outside the aperture edges. This method can precisely
control the geometric profile of high fill factor triangular microlens array.
The experimental results showed that the triangular micro-lens array in
photoresist could be formed automatically when the printing gap ranged from 240
micrometers to 840 micrometers. The gapless triangular microlens array will be
used to increases of luminance for backlight module of liquid crystal displays.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/handle/2042/16838
Mass Spectrum and Bounds on the Couplings in Yukawa Models With Mirror-Fermions
The symmetric Yukawa model with mirror-fermions
in the limit where the mirror-fermion is decoupled is studied both analytically
and numerically. The bare scalar self-coupling is fixed at zero and
infinity. The phase structure is explored and the relevant phase transition is
found to be consistent with a second order one. The fermionic mass spectrum
close to that transition is discussed and a first non-perturbative estimate of
the influence of fermions on the upper and lower bounds on the renormalized
scalar self-coupling is given. Numerical results are confronted with
perturbative predictions.Comment: 7 (Latex) page
Internal Gravity Waves Modulate the Apparent Misalignment of Exoplanets around Hot Stars
We propose that the observed misalignment between extra-solar planets and
their hot host stars can be explained by angular momentum transport within the
host star. Observations have shown that this misalignment is preferentially
around hot stars, which have convective cores and extended radiative envelopes.
This situation is amenable to substantial angular momentum transport by
internal gravity waves (IGW) generated at the convective-radiative interface.
Here we present numerical simulations of this process and show that IGW can
modulate the surface rotation of the star. With these two- dimensional
simulations we show that IGW could explain the retrograde orbits observed in
systems such as HAT-P-6 and HAT-P-7, however, extension to high obliquity
objects will await future three- dimensional simulations. We note that these
results also imply that individual massive stars should show temporal
variations in their v sini measurements.Comment: 6 pages, 2 figures, Accepted for publication in ApJ
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