"We also propose an experimental
realization, and under ideal circumstances this lens can exhibit subwavelength resolution, limited
only by the strength of the time-reversed signal."
Pendry, J. B. (2008). Time Reversal and Negative Refraction. Science, 322(5898), 71–73. doi:10.1126/science.1162087
This quote: Somewhat later in (10), a practical
realization of this mathematical scheme was pro-
posed, but only a partial realization. Whereas the
scheme is effective for the far field, it does not
reproduce the same boundary conditions for eva-
nescent states and therefore supports no surface
modes. In fact, a realization of the boundary con-
dition had already been implemented in (11), but
again only effective for the far field.
Because there are no phases associated with
evanescent waves, it should come as a surprise
that the lensing process shows telltale signs of
conventional interference, particularly in the way
the waves contributing to Eq. 3 add up con-
structively and destructively at the focal plane.
Because it involves nonradiative modes, we will
refer to this unconventional form of focusing as
radiationless interference.
In order to meet the electromagnetic characteristics requirements of WPT [Wireless Power Transfer] systems, high-performance Mn-Zn and Ni-Zn ferrites, amorphous, nanocrystalline, and metamaterials have been developed rapidly in recent years. This paper introduces an extensive review of the magnetic materials of WPT systems, concluding with the state-of-the-art WPT technology and the development and application of high-performance magnetic materials.
The experimental results show that the WPT system containing metamaterials can achieve a system coupling efficiency of 81.7% at a transmission distance of 1.5 m. Compared with the device without metamaterials, the coupling efficiency was improved by 21%.
the principle of magnetic field shielding is to use magnetic materials to direct the magnetic flux
along the path close to the coupling coil, which improves the coil’s mutual and self-in-
ductance, ultimately achieving a reduction in the leakage magnetic field strength of the
WPT system [245].
Generally, perfect lensing relies on two effects: negative refraction, to focus the diverging rays, and amplification of evanescent waves, to restore the subwavelength spectrum [1, 20].
strong, intra-layer covalent bonding and weak, inter-layer van der Waals bonding.
That's boron nitride - should be the same for graphene?
In graphene each carbon atom is linked to three neighbors by three covalent bonds. Thereby, interfaces such as the ones materialized by the dashed vertical lines in figure 2 or those considered in reference [26] may be chemically unstable
Due to the dislocations, the p-type region effectively behaves as the complementary material of the n-type region. Within the effective model approximation, the system behaves as a perfect lens.
http://diposit.ub.edu/dspace/bitstream/2445/127169/1/Guany%202_Grafe%CC%80_G_Sabat%C3%A9.pdf
In 2012 professor Mikhail Katsnelson even speculated that in the future a particle accelerator, like the one in Switzerland, could be reduced to the size of 1 cm2 in a graphene layer, with no need for building megalithic structures (11)
https://www.nature.com/articles/s41467-022-30079-z
An Archimedes' screw for light
something quite spectacular happens: the velocity of both RHP and LHP
waves first tends to zero near the origin, the waves being effectively
led to a halt by the screw, then becomes negative and tends to − ∞,
implying that the optical drag becomes now infinite and opposite to the
direction of the screw. In addition, while LHP states remain stable,
the instability affecting RHP modes reaches the origin, implying a
bandwidth-unlimited instability, so that the system can now amplify RHP
waves of any frequency.
Nonlocal effects of metamaterials
Freed from constraints such as reciprocity and energy conservation, these systems can enable new and exotic wave behaviours.
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