1,008,930 research outputs found
Light controlled photon tunneling
Recent measurements of photon tunneling through individual subwavelength
pinholes in a gold film covered with a layer of polydiacetylene (Phys. Rev.
Letters 88, 187402 (2002)) provided strong indication of "photon blockade"
effect similar to Coulomb blockade phenomenon observed in single-electron
tunneling experiments. Here we report first observation of photon tunneling
been blocked (gated) by light at a different wavelength. This observation
suggests possibility of building new class of photon tunneling gating devices
for all-optical signal processing.Comment: 11 pages, 3 figure
"Breathing" rogue wave observed in numerical experiment
Numerical simulations of the recently derived fully nonlinear equations of
motion for weakly three-dimensional water waves [V.P. Ruban, Phys. Rev. E {\bf
71}, 055303(R) (2005)] with quasi-random initial conditions are reported, which
show the spontaneous formation of a single extreme wave on the deep water. This
rogue wave behaves in an oscillating manner and exists for a relatively long
time (many wave periods) without significant change of its maximal amplitude.Comment: 6 pages, 12 figure
Solutions of Podolsky's Electrodynamics Equation in the First-Order Formalism
The Podolsky generalized electrodynamics with higher derivatives is
formulated in the first-order formalism. The first-order relativistic wave
equation in the 20-dimensional matrix form is derived. We prove that the
matrices of the equation obey the Petiau-Duffin-Kemmer algebra. The
Hermitianizing matrix and Lagrangian in the first-order formalism are given.
The projection operators extracting solutions of field equations for states
with definite energy-momentum and spin projections are obtained, and we find
the density matrix for the massive state. The -matrix Schrodinger
form of the equation is derived, and the Hamiltonian is obtained. Projection
operators extracting the physical eigenvalues of the Hamiltonian are found.Comment: 17 pages, minor corrections, published versio
Dissipation through spin Coulomb drag in electronic spin dynamics
Spin Coulomb drag (SCD) constitutes an intrinsic source of dissipation for
spin currents in metals and semiconductors. We discuss the power loss due to
SCD in potential spintronics devices and analyze in detail the associated
damping of collective spin-density excitations. It is found that SCD
contributes substantially to the linewidth of intersubband spin plasmons in
parabolic quantum wells, which suggests the possibility of a purely optical
quantitative measurement of the SCD effect by means of inelastic light
scattering
Sleptonarium (Constraints on the CP and Flavour Pattern of Scalar Lepton Masses)
The constraints on the flavour and CP structure of scalar lepton mass
matrices are systematically collected. The display of the resulting upper
bounds on the lepton -slepton misalignment parameters is designed for an easy
inspection of very large classes of models and the formula are arranged so as
to suggest useful approximations. Interferences among the different
contributions to lepton flavour violating transitions and lepton electric and
magnetic dipole moments of generic character can either tighten or loose the
bounds. A combined analysis of all rare leptonic transitions can disentangle
the different contributions to yield hints on several phenomenological issues.
The possible impact of these results on the study of the slepton misalignment
originated in the seesaw mechanism and grand-unified theories is emphasized
since the planned experiments are getting close to the precision required in
such tests.Comment: 29 pages, 13 figures; v3: corrected misprints in appendix
The low temperature Fulde-Ferrell-Larkin-Ovchinnikov phases in 3 dimensions
We consider the nature of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phases
in three dimensions at low temperature. We introduce a new method to handle the
quasiclassical equations for superconductors with space dependent order
parameter, which makes use of a Fourier expansion. This allows us to show that,
at T=0, an order parameter given by the linear combination of three cosines
oscillating in orthogonal directions is preferred over the standard single
cosine solution. The transition from the normal state to this phase is first
order, and quite generally the transition below the tricritical point to the
FFLO phases is always first order.Comment: 4 pages, revtex, 1 figur
Electrochemical Potential Monitoring of Corrosion and Inhibitors Protection of Mild Steel Embedded in Concrete in NaCl Solution
The corrosion and protection behaviour of mild steel embedded in concrete, and partially immersed in 3.5% sodium chloride solution, was studied in this investigation at ambient temperature by potential monitoring technique. The work was performed with a digital multimeter and a Cu/CuSO4 electrode (CSE) as the reference electrode. Extracts of pawpaw (carica papaya) leaves and sodium nitrite in different concentrations were separately and in combination, used as inhibitors. This paper reports the observed electrochemical response from the electrode potential monitoring of the embedded mild steel during the experiments. The results obtained, showed a reduction in the active corrosion reactions behaviour of the embedded mild steel in concrete admixed with different concentrations of sodium nitrite and the pawpaw leaves extracts thus indicating corrosion inhibition characteristic. The observed inhibition was attributed to the protective film provided on the steel’s surface in the concrete by the complex chemical compounds of the plant leaves’ extracts and the reaction of sodium nitrite with the alkaline environment of the concrete and its constituents. The combination of pawpaw extracts and the NaNO2 solution provided effective corrosion inhibition of the embedded steel by synergism. The 100% concentration of each of the inhibitors and when in combinations, exhibited the most effective corrosion inhibition performanc
Nonlinear internal models for output regulation
In this paper we show how nonlinear internal models can be effectively used
in the design of output regulators for nonlinear systems. This result provides
a significant enhancement of the non-equilibrium theory for output regulation,
which we have presented in the recent paper entitled "Limit Sets, Zero
Dynamics, and Internal Models in the Problem of Nonlinear Output Regulation"
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