152,374 research outputs found
Metastable states of surface plasmon vacuum near the interface between metal and nonlinear dielectric
Zero-point fluctuations of surface plasmon modes near the interface between
metal and nonlinear dielectric are shown to produce a thin layer of altered
dielectric constant near the interface. This effect may be sufficiently large
to produce multiple metastable states of the surface plasmon vacuum.Comment: 4 pages, 2 figure
Comparison of near-interface traps in AlO/4H-SiC and AlO/SiO/4H-SiC structures
Aluminum oxide (Al2O3) has been grown by atomic layer deposition on n-type
4H-SiC with and without a thin silicon dioxide (SiO2) intermediate layer. By
means of Capacitance Voltage and Thermal Dielectric Relaxation Current
measurements, the interface properties have been investigated. Whereas for the
samples with an interfacial SiO2 layer the highest near-interface trap density
is found at 0.3 eV below the conduction band edge, Ec, the samples with only
the Al2O3 dielectric exhibit a nearly trap free region close to Ec. For the
Al2O3/SiC interface, the highest trap density appears between 0.4 to 0.6 eV
below Ec. The results indicate the possibility for SiC-based MOSFETs with Al2O3
as the gate dielectric layer in future high performance devices.Comment: 3 figures. Applied Physics Letters, accepted for publicatio
Electric field inside a "Rossky cavity" in uniformly polarized water
Electric field produced inside a solute by a uniformly polarized liquid is
strongly affected by dipolar polarization of the liquid at the interface. We
show, by numerical simulations, that the electric "cavity" field inside a
hydrated non-polar solute does not follow the predictions of standard Maxwell's
electrostatics of dielectrics. Instead, the field inside the solute tends, with
increasing solute size, to the limit predicted by the Lorentz virtual cavity.
The standard paradigm fails because of its reliance on the surface charge
density at the dielectric interface determined by the boundary conditions of
the Maxwell dielectric. The interface of a polar liquid instead carries a
preferential in-plane orientation of the surface dipoles thus producing
virtually no surface charge. The resulting boundary conditions for
electrostatic problems differ from the traditional recipes, affecting the
microscopic and macroscopic fields based on them. We show that relatively small
differences in cavity fields propagate into significant differences in the
dielectric constant of an ideal mixture. The slope of the dielectric increment
of the mixture versus the solute concentration depends strongly on which
polarization scenario at the interface is realized. A much steeper slope found
in the case of Lorentz polarization also implies a higher free energy penalty
for polarizing such mixtures.Comment: 9 pages, 8 figure
- …