1,926 research outputs found
Negative reflections of electromagnetic waves in chiral media
We investigate the reflection properties of electromagnetic/optical waves in
isotropic chiral media. When the chiral parameter is strong enough, we show
that an unusual \emph{negative reflection} occurs at the interface of the
chiral medium and a perfectly conducting plane, where the incident wave and one
of reflected eigenwaves lie in the same side of the boundary normal. Using such
a property, we further demonstrate that such a conducting plane can be used for
focusing in the strong chiral medium. The related equations under paraxial
optics approximation are deduced. In a special case of chiral medium, the
chiral nihility, one of the bi-reflections disappears and only single reflected
eigenwave exists, which goes exactly opposite to the incident wave. Hence the
incident and reflected electric fields will cancel each other to yield a zero
total electric field. In another word, any electromagnetic waves entering the
chiral nihility with perfectly conducting plane will disappear.Comment: 5 pages, 5 figure
Collective quantum phase slips in multiple nanowire junctions
Realization of robust coherent quantum phase slips represents a significant
experimental challenge. Here we propose a new design consisting of multiple
nanowire junctions to realize a phase-slip flux qubit. It admits good
tunability provided by gate voltages applied on superconducting islands
separating nanowire junctions. In addition, the gates and junctions can be
identical or distinct to each other leading to symmetric and asymmetric setups.
We find that the asymmetry can improve the performance of the proposed device,
compared with the symmetric case. In particular, it can enhance the effective
rate of collective quantum phase slips. Furthermore, we demonstrate how to
couple two such devices via a mutual inductance. This is potentially useful for
quantum gate operations. Our investigation on how symmetry in multiple nanowire
junctions affects the device performance should be useful for the application
of phase-slip flux qubits in quantum information processing and quantum
metrology.Comment: 12 pages, 6 figure
One dimensional chain of quantum molecule motors as a mathematical physics model for muscle fibre
A quantum chain model of many molecule motors is proposed as a mathematical
physics theory on the microscopic modeling of classical force-velocity relation
and tension transients of muscle fibre. We proposed quantum many-particle
Hamiltonian to predict the force-velocity relation for the slow release of
muscle fibre which has no empirical relation yet, it is much more complicate
than hyperbolic relation. Using the same Hamiltonian, we predicted the
mathematical force-velocity relation when the muscle is stimulated by
alternative electric current. The discrepancy between input electric frequency
and the muscle oscillation frequency has a physical understanding by Doppler
effect in this quantum chain model. Further more, we apply quantum physics
phenomena to explore the tension time course of cardiac muscle and insect
flight muscle. Most of the experimental tension transients curves found their
correspondence in the theoretical output of quantum two-level and three-level
model. Mathematically modeling electric stimulus as photons exciting a quantum
three-level particle reproduced most tension transient curves of water bug
Lethocerus Maximus.Comment: 16 pages, 12 figures, Arguments are adde
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