29,301 research outputs found
Turning a Band Insulator Into an Exotic Superconductor
Understanding exotic, non s--wave--like states of Cooper pairs is important
and may lead to new superconductors with higher critical temperatures and novel
properties. Their existence is known to be possible but has always been thought
to be associated with non--traditional mechanisms of superconductivity where
electronic correlations play an important role. Here we use a first principles
linear response calculation to show that in doped BiSe an
unconventional p--wave--like state can be favored via a conventional
phonon--mediated mechanism, as driven by an unusual, almost singular behavior
of the electron--phonon interaction at long wavelengths. This may provide a new
platform for our understanding superconductivity phenomena in doped band
insulators.Comment: Published versio
How Can Psychological Contagion Effect Be Attenuated? The Role of Boundary Effect on Menu Design
Psychological effects can be greatly influential for the foodservice industry, especially in menu design. Presenting dish pictures is a common practice on menus, but because of the psychological contagion effect, this practice could decrease consumers’ evaluations of dishes, sometimes without the awareness of consumers, let alone restaurant managers. This research aims to explore the potential threats of a psychological contagion by considering how dishes that make consumers feel uncomfortable can affect their evaluations of dishes located nearby. It further examines how a psychological contagion can be attenuated when a visual boundary is placed between a discomfiting dish and a target dish. The results demonstrate the occurrence of psychological contagion in menu design. The interaction between psychological contagions and visual boundaries suggest that the psychological contagion can be attenuated through visual boundaries
A kernel method for non-linear systems identification – infinite degree volterra series estimation
Volterra series expansions are widely used in analyzing
and solving the problems of non-linear dynamical
systems. However, the problem that the number of
terms to be determined increases exponentially with the
order of the expansion restricts its practical application.
In practice, Volterra series expansions are truncated
severely so that they may not give accurate representations
of the original system. To address this problem,
kernel methods are shown to be deserving of exploration.
In this report, we make use of an existing result
from the theory of approximation in reproducing kernel
Hilbert space (RKHS) that has not yet been exploited in
the systems identification field. An exponential kernel
method, based on an RKHS called a generalized Fock
space, is introduced, to model non-linear dynamical systems
and to specify the corresponding Volterra series
expansion. In this way a non-linear dynamical system
can be modelled using a finite memory length, infinite
degree Volterra series expansion, thus reducing the
source of approximation error solely to truncation in
time. We can also, in principle, recover any coefficient
in the Volterra series
Computational Design of Axion Insulators Based on 5d Spinels Compounds
Based on density functional calculation with LDA+U method, we propose that
hypothetical Osmium compounds such as CaOs2O4 and SrOs2O4 can be stabilized in
the geometrically frustrated spinel crystal structure. They also show some
exotic electronic and magnetic properties in a reasonable range of on-site
Coulomb correlation U such as ferromagnetism and orbital magnetoelectric effect
characteristic to Axion electrodynamics. Other electronic phases including 3D
Dirac metal and Mott insulator exist and would make perspective 5d spinels
ideal for applications.Comment: 5 pages, 3 figure
- …