1,867 research outputs found
Low Energy Theorem for SUSY Breaking with Gauge Supermultiplets
Low energy theorems of Nambu-Goldstone fermion associated with spontaneously
broken supersymmetry are studied for gauge supermultiplets. Two possible terms
in the effective Lagrangian are needed to deal with massless gaugino and/or
massless gauge boson. As an illustrative example, a concrete model is worked
out which can interpolate massless as well as massive gaugino and/or gauge
boson to examine the low energy effective interaction of NG-fermion.Comment: 14page
Spin-state transition and phase separation in multi-orbital Hubbard model
We study spin-state transition and phase separation involving this transition
based on the milti-orbital Hubbard model. Multiple spin states are realized by
changing the energy separation between the two orbitals and the on-site Hund
coupling. By utilizing the variational Monte-Carlo simulation, we analyze the
electronic and magnetic structures in hole doped and undoped states. Electronic
phase separation occurs between the low-spin band insulating state and the
high-spin ferromagnetic metallic one. Difference of the band widths in the two
orbitals is of prime importance for the spin-state transition and the phase
separation.Comment: 5 pages, 5 figure
Universality in Open Quantum Spin Chains with Non-Reciprocity
We investigate the impact of non-reciprocity on universality and critical
phenomena in open quantum systems. Non-reciprocal open quantum systems often
have an exotic spectral sensitivity to boundary conditions, known as the
Liouvillian skin effect (LSE). By considering an open quantum XXZ spin chain
that exhibits LSE, we demonstrate the existence of a universal scaling regime
that is not affected by the presence of the LSE. We resolve the critical
exponents, which differ from those of free fermions, via tensor network methods
and demonstrate that observables exhibit a universal scaling collapse,
irrespective of the reciprocity. We find that the LSE only becomes relevant
when a healing length scale at the system's edge (which is
different to the localization length of the eigenstate of the Liouvillian)
exceeds the system size, allowing edge properties to dominate the physics. We
expect this result to be a generic feature of non-reciprocal models in the
vicinity of a critical point.Comment: 4 figure
Non-Stationary Dark Energy Around a Black Hole
Numerical simulations of the accretion of test scalar fields with
non-standard kinetic terms (of the k-essence type) onto a Schwarzschild black
hole are performed. We find a full dynamical solution for the spherical
accretion of a Dirac-Born-Infeld type scalar field. The simulations show that
the accretion eventually settles down to a well known stationary solution. This
particular analytical steady state solution maintains two separate horizons.
The standard horizon is for the usual particles propagating with the limiting
speed of light, while the other sonic horizon is for the k-essence
perturbations propagating with the speed of sound around this accreting
background. For the case where the k-essence perturbations propagate
superluminally, we show that one can send signals from within a black hole
during the approach to the stationary solution. We also find that a ghost
condensate model settles down to a stationary solution during the accretion
process.Comment: 8 pages, 10 figure
A computational scheme to evaluate Hamaker constants of molecules with practical size and anisotropy
We propose a computational scheme to evaluate Hamaker constants, , of
molecules with practical sizes and anisotropies. Upon the increasing
feasibility of diffusion Monte Carlo (DMC) methods to evaluate binding curves
for such molecules to extract the constants, we discussed how to treat the
averaging over anisotropy and how to correct the bias due to the
non-additivity. We have developed a computational procedure for dealing with
the anisotropy and reducing statistical errors and biases in DMC valuations,
based on possible validations on predicted . We applied the scheme to
cyclohexasilane molecule, SiH, used in 'printed electronics'
fabrications, getting [zJ], being in plausible range
supported even by other possible extrapolations. The scheme provided here would
open a way to use handy {\it ab initio} evaluations to predict wettabilities as
in the form of materials informatics over broader molecules.Comment: The manuscript was revised according to review comment
Categorization of indoor places by combining local binary pattern histograms of range and reflectance data from laser range finders
This paper presents an approach to categorize typical places in indoor environments using 3D scans provided by a laser range finder. Examples of such places are offices, laboratories, or kitchens. In our method, we combine the range and reflectance data from the laser scan for the final categorization of places. Range and reflectance images are transformed into histograms of local binary patterns and combined into a single feature vector. This vector is later classified using support vector machines. The results of the presented experiments demonstrate the capability of our technique to categorize indoor places with high accuracy. We also show that the combination of range and reflectance information improves the final categorization results in comparison with a single modality
Theory of Transport in Ferroelectric Capacitors
The spontaneous order of electric and magnetic dipoles in ferroelectrics and ferromagnets even at high temperatures is both fascinating and useful. Transport of magnetism in the form of spin currents is vigorously studied in spintronics, but the polarization current of the ferroelectric order has escaped attention. We therefore present a time-dependent diffusion theory for heat and polarization transport in a planar ferroelectric capacitor with parameters derived from a one-dimensional phonon model. We predict steady-state Seebeck and transient Peltier effects that await experimental discovery
Thermoelectric Polarization Transport in Ferroelectric Ballistic Point Contacts
We formulate a scattering theory of polarization and heat transport through a ballistic ferroelectric point contact. We predict a polarization current under either an electric field or a temperature difference that depends strongly on the direction of the ferroelectric order and can be detected by its magnetic stray field and associated thermovoltage and Peltier effect
Magnonics vs. Ferronics
Magnons are the elementary excitations of the magnetic order that carry spin,
momentum, and energy. Here we compare the magnon with the ferron, i.e. the
elementary excitation of the electric dipolar order that transports
polarization and heat in ferroelectrics.Comment: Submitted for publication in the Virtual Special Issue (VSI) on
Magnonics of the Journal of Magnetism and Magnetic Materials, in honor of
Prof. Servio Rezende's 80th birthda
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