22,364 research outputs found
Super-resolution image transfer by a vortex-like metamaterial
We propose a vortex-like metamaterial device that is capable of transferring
image along a spiral route without losing subwavelength information of the
image. The super-resolution image can be guided and magnified at the same time
with one single design. Our design may provide insights in manipulating
super-resolution image in a more flexible manner. Examples are given and
illustrated with numerical simulations.Comment: 7 pages, 6 figure
Coherent control of high-harmonic generation using waveform-synthesized chirped laser fields
We show that waveform-synthesized chirped laser fields are efficient tools for coherent harmonic control. A single harmonic order, or two harmonic orders, can be selectively enhanced by using a two-color field allowing a moderate linear chirp for each color. Different harmonic orders within a wide spectral range can be selectively enhanced by adjusting the laser parameters. Our theory bridges two current harmonic control techniques, namely, single-color phase shaping and multicolor amplitude synthesis, and opens the door to new harmonic control possibilities
Half Metallic Bilayer Graphene
Charge neutral bilayer graphene has a gapped ground state as transport
experiments demonstrate. One of the plausible such ground states is layered
antiferromagnetic spin density wave (LAF) state, where the spins in top and
bottom layers have same magnitude with opposite directions. We propose that
lightly charged bilayer graphene in an electric field perpendicular to the
graphene plane may be a half metal as a consequence of the inversion and
particle-hole symmetry broken in the LAF state. We show this explicitly by
using a mean field theory on a 2-layer Hubbard model for the bilayer graphene.Comment: 4+ pages, 4 figure
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