1,593 research outputs found
Transfer of Gravitational Information through a Quantum Channel
Gravitational information is incorporated into an atomic state by correlation
of the internal and external degrees of freedom of the atom, in the present
study of the atomic interferometer. Thus it is difficult to transfer
information by using a standard teleportation scheme. In this paper, we propose
a novel scheme for the transfer of gravitational information through a quantum
channel provided by the entangled atomic state. Significantly, the existence of
a quantum channel suppresses phase noise, improving the sensitivity of the
atomic interferometer. Thus our proposal provides novel readout mechanism for
the interferometer with an improved signal-to-noise ratio
Disorder effect of resonant spin Hall effect in a tilted magnetic field
We study the disorder effect of resonant spin Hall effect in a two-dimension
electron system with Rashba coupling in the presence of a tilted magnetic
field. The competition between the Rashba coupling and the Zeeman coupling
leads to the energy crossing of the Landau levels, which gives rise to the
resonant spin Hall effect. Utilizing the Streda's formula within the
self-consistent Born approximation, we find that the impurity scattering
broadens the energy levels, and the resonant spin Hall conductance exhibits a
double peak around the resonant point, which is recovered in an applied titled
magnetic field.Comment: 6 pages, 4 figure
Electric field modulation of topological order in thin film semiconductors
We propose a method that can consecutively modulate the topological orders or
the number of helical edge states in ultrathin film semiconductors without a
magnetic field. By applying a staggered periodic potential, the system
undergoes a transition from a topological trivial insulating state into a
non-trivial one with helical edge states emerging in the band gap. Further
study demonstrates that the number of helical edge state can be modulated by
the amplitude and the geometry of the electric potential in a step-wise
fashion, which is analogous to tuning the integer quantum Hall conductance by a
megntic field. We address the feasibility of experimental measurement of this
topological transition.Comment: 4 pages, 4 figure
Magnetic anisotropy and reversal in epitaxial Fe/MgO(001) films revisited
We investigate the magnetization reversal in Fe/MgO(001) films with fourfold
in-plane magnetic anisotropy and an additional uniaxial anisotropy whose
orientation and strength are tuned using different growth geometries and post
growth treatments. The previously adopted mechanism of 180^{o} domain wall
nucleation clearly fails to explain the observed 180^{o} magnetization
reversal. A new reversal mechanism with two successive domain wall nucleations
consistently predicts the switching fields for all field orientations. Our
results are relevant for a correct interpretation of magnetization reversal in
many other epitaxial metallic and semiconducting thin films.Comment: 4 pages, 4 figure
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