We present a theoretical investigation of a semiconductor quantum dot interacting with a strongly localized optical field as encountered in high-resolution near-field optical microscopy. The strong gradients of these localized fields suggest that higher-order multipolar interactions will affect the standard electric dipole transition rates and selection rules. For a semiconductor quantum dot in...

I suggest wave equations for the scalar, pseudoscalar, vector, and pseudovector fields with different masses for spin zero and one states. Tensor, matrix, and quaternion formulations of fields with two mass and spin states are considered. This is the generalization of the DiracKähler equation on the case of different masses of fields with spin one and zero. The equation matrices obtained are si...

Multipole expansions depend on the coordinate system, so that coefficients of multipole moments can be set equal to zero by an appropriate choice of coordinates. Therefore, it is meaningless to say that a physical system has a nonvanishing quadrupole moment, say, without specifying which coordinate system is used. (Except if this moment is the lowest non-vanishing one.) This result is demonstra...

Based on the membrane currents generated by an action potential in a biologically realistic model of a pyramidal, hippocampal cell within rat CA1, we perform a moment expansion of the extracellular field potential. We decompose the potential into both inverse and classical moments and show that this method is a rapid and efficient way to calculate the extracellular field both near and far from ...

In homonuclear molecules, such as H2, the electric dipole transitions are strongly forbidden, and the transitions between rovibrational states are of the electric quadrupole type. We show however, that magnetic dipole transitions also take place, although are significantly weaker. We evaluate the probabilities of such transitions between several lowest rotational states and compare them with th...

We experimentally investigate an optical frequency standard based on the 467 nm (642 THz) electric-octupole reference transition (2)S(1/2)(F=0)→(2)F(7/2)(F=3) in a single trapped (171)Yb(+) ion. The extraordinary features of this transition result from the long natural lifetime and from the 4f(13)6s(2) configuration of the upper state. The electric-quadrupole moment of the (2)F(7/2) state is me...

A simple tensorial contraction method has been developed to obtain analytical formulae for X-ray resonant magnetic scattering. First, the method has been applied considering electric dipole-dipole and electric quadrupole-quadrupole scattering in the isolated-atom approximation. The results have been compared with previous work. The same method has then been extended to non-spherical systems by ...

We study the effects of model-dependent contributions and the electric quadrupole moment of vector mesons in the decays V − → PP 0γ and τ → νV γ. Their interference with the amplitude originating from the radiation due to electric charges vanishes for photons emitted collinearly to the charged particle in the final state. This brings further support to our claim in previous works, that measurem...

A rotating star’s oblateness creates a deformation in the gravitational field outside the star, which is measured by the quadrupole-moment tensor. We consider the effect of the quadrupole moment on the orbital motion and rate of inspiral of a compact binary system, composed of neutron stars and/or black holes. We find that in the case of circular orbits, the quadrupole-monopole interaction affe...