Probing electric and magnetic vacuum fluctuations with quantum dots

The electromagnetic-vacuum-field fluctuations are intimately linked to the process of spontaneous emission of light. Atomic emitters cannot probe electric- and magnetic-field fluctuations simultaneously because electric and magnetic transitions correspond to different selection rules. In this paper we show that semiconductor quantum dots are fundamentally different and are capable of mediating electric-dipole, magnetic-dipole, and electric-quadrupole transitions on a single electronic resonance. As a consequence, quantum dots can probe electric and magnetic fields simultaneously and can thus be applied for sensing the electromagnetic environment of complex photonic nanostructures. Our study opens the prospect of interfacing quantum dots with optical metamaterials for tailoring the electric and magnetic light-matter interaction at the single-emitter level.Comment: 6 pages, 4 figure

Influence of Spurious Waves on the Performance of Active Absorption Systems in Oblique Waves

Existing active absorption systems do not take into account the spurious waves caused by the segmentation of the wavemaker. Thus, the theoretical estimated performance curves for oblique waves are only valid for infinitely narrow segments. In the present paper, it is demonstrated that by ignoring the spurious waves, an unstable system might be designed for box-mode paddles (piecewise constant segmentation). For vertical hinged pistons (piecewise linear segmentation), the results are the opposite, as the stability of the system is improved at high frequencies when a finite paddle width is considered. It is also shown that finite discretization leads to a directional influence in the system, even for a pseudo-3D active absorption system. This effect is more pronounced for vertical hinged systems compared to box-mode paddles

Separation of Long-Crested Nonlinear Bichromatic Waves into Incident and Reflected Components

Methods for the separation of long-crested linear waves into incident and reflected waves have existed for more than 40 years. The present paper presents a new method for the separation of nonlinear bichromatic long-crested waves into incident and reflected components, as well as into free and bound components. The new method is an extension of a recently proposed method for the separation of nonlinear regular waves. The new methods include both bound and free higher harmonics, which is important for nonlinear waves. The applied separation method covers interactions to the third order, but can easily be extended to a higher orders. Synthetic tests, as well as physical model tests, showed that the method accurately predict the bound amplitudes and incident and reflected surface elevations of nonlinear bichromatic waves. The new method is important in order to be able to describe the detailed characteristics of nonlinear bichromatic waves and their reflection