6,651 research outputs found
Majorana zero modes in a quantum Ising chain with longer-ranged interactions
A one-dimensional Ising model in a transverse field can be mapped onto a
system of spinless fermions with p-wave superconductivity. In the weak-coupling
BCS regime, it exhibits a zero energy Majorana mode at each end of the chain.
Here, we consider a variation of the model, which represents a superconductor
with longer ranged kinetic energy and pairing amplitudes, as is likely to occur
in more realistic systems. It possesses a richer zero temperature phase diagram
and has several quantum phase transitions. From an exact solution of the model
these phases can be classified according to the number of Majorana zero modes
of an open chain: 0, 1, or 2 at each end. The model posseses a multicritical
point where phases with 0, 1, and 2 Majorana end modes meet. The number of
Majorana modes at each end of the chain is identical to the topological winding
number of the Anderson's pseudospin vector that describes the BCS Hamiltonian.
The topological classification of the phases requires a unitary time-reversal
symmetry to be present. When this symmetry is broken, only the number of
Majorana end modes modulo 2 can be used to distinguish two phases. In one of
the regimes, the wave functions of the two phase shifted Majorana zero modes
decays exponentially in space but but in an oscillatory manner. The wavelength
of oscillation is identical to the asymptotic connected spin-spin correlation
of the XY-model in a transverse field to which our model is dual.Comment: 11 pages, 8 figures; brief clarifying comments added; few new
references; this version is accepted in Phys. Rev.
Application of molecular biomarkers in epidemiology.
The principal conclusions and opportunities that can be drawn from this conference are as follows. The meeting demonstrated the large communication gap that still exists between most epidemiologists and laboratory scientists. This problem could be overcome if epidemiologists worked closely with laboratory scientists at the outset of any project so that a better understanding could be built between them. Epidemiologists need simple, well-characterized, reproducible assays that can be applied to hundreds or thousands of people. Most laboratory scientists have little interest in running large numbers of assays, but wish to continually refine their methods so that they stay on the "cutting edge" of basic research. This problem could be overcome if the new laboratory technology could be transferred to contract laboratories or small companies. Problems of technology transfer therefore need to be addressed. Current and new biomarkers need to be better validated in the field and by studying animal models. More information on the background expression of biomarkers in the general population is needed (i.e. what is the normal range?). Ethical issues, such as the possibility that biomarkers of susceptibility could be used to exclude people from the workplace, need to be addressed
Two Circular-Rotational Eigenmodes in Vortex Gyrotropic Motions in Soft Magnetic Nanodots
We found, by micromagnetic numerical and analytical calculations, that the
clockwise (CW) and counterclockwise (CCW) circular-rotational motions of a
magnetic vortex core in a soft magnetic circular nanodot are the elementary
eigenmodes existing in the gyrotropic motion with respect to the corresponding
CW and CCW circular-rotational-field eigenbasis. Any steady-state vortex
gyrotropic motions driven by a linearly polarized oscillating in-plane magnetic
field in the linear regime can be perfectly understood according to the
superposition of the two circular eigenmodes, which show asymmetric resonance
characteristics reflecting the vortex polarization. The relative magnitudes in
the amplitude and phase between the CCW and CW eigenmodes determine the
elongation and orientation of the orbital trajectories of the vortex core
motions, respectively, which trajectories vary with the polarization and
chirality of the given vortex as well as the field frequency across the
resonance frequency.Comment: 30 pages, 7 figure
Bound Cations Significantly Stabilize the Structure of Multiprotein Complexes in the Gas Phase
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91320/1/5790_ftp.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/91320/2/ange_201109127_sm_miscellaneous_information.pd
Inverse Tunneling Magnetoresistance in nanoscale Magnetic Tunnel Junctions
We report on our theoretical study of the inverse TMR effect in the spin
polarized transport through a narrow channel. In the weak tunneling limit, we
find the ordinary positive TMR. The TMR changes its sign as the transmission
probability becomes large close to a unity. Our results might be relevant to
the magnetic tunnel junction with a pinhole or a quantum point contact.Comment: 11 pages, 4 figures, To be published in Phys. Rev. B (in press
Criterion for transformation of transverse domain wall to vortex or antivortex wall in soft magnetic thin-film nanostripes
We report on the criterion for the dynamic transformation of the internal
structure of moving domain walls (DWs) in soft magnetic thin-film nanostripes
above the Walker threshold field, Hw. In order for the process of
transformation from transverse wall (TW) to vortex wall (VW) or antivortex wall
(AVW) occurs, the edge-soliton core of the TW-type DW should grow sufficiently
to the full width at half maximum of the out-of-plane magnetizations of the
core area of the stabilized vortex (or antivortex) by moving inward along the
transverse (width) direction. Upon completion of the nucleation of the vortex
(antivortex) core, the VW (AVW) is stabilized, and then its core accompanies
the gyrotropic motion in a potential well (hill) of a given nanostripe. Field
strengths exceeding the Hw, which is the onset field of DW velocity breakdown,
are not sufficient but necessary conditions for dynamic DW transformation
The color of smiling: computational synaesthesia of facial expressions
This note gives a preliminary account of the transcoding or rechanneling
problem between different stimuli as it is of interest for the natural
interaction or affective computing fields. By the consideration of a simple
example, namely the color response of an affective lamp to a sensed facial
expression, we frame the problem within an information- theoretic perspective.
A full justification in terms of the Information Bottleneck principle promotes
a latent affective space, hitherto surmised as an appealing and intuitive
solution, as a suitable mediator between the different stimuli.Comment: Submitted to: 18th International Conference on Image Analysis and
Processing (ICIAP 2015), 7-11 September 2015, Genova, Ital
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