Harmonic functions provide a method for implementingpotentialeld path planning. Since they produce smooth vector elds which are free of spurious local minima, they also provide an ideal mechanism for implementing velocity-based control. This paper describes the implementation of velocity control using harmonic functions. The resulting control system is termed \Harmonic Control" and is quite rob...

We study experimentally second-harmonic generation from arrays of split-ring resonators at oblique incidence and find conditions of more than 30-fold enhancement of the emitted second harmonic with respect to normal incidence. We show that these conditions agree well with a nonlinear Rayleigh-Wood anomaly relation and the existence of a surface lattice resonance at the second harmonic. The exis...

The dynamics of energy relaxation in thermalized oneand twodimensional arrays with nonlinear interactions depend in detail on the interactions and, in some cases, on dimensionality. We describe and explain these differences for arrays of the Fermi-Pasta-Ulam type. In particular, we focus on the roles of harmonic contributions to the interactions and of breathers in the relaxation process. PACS ...

We address the problem of simulating pair-interaction Hamiltonians in n node quantum networks where the subsystems have arbitrary, possibly different, dimensions. We show that any pair-interaction can be used to simulate any other by applying sequences of appropriate local control sequences. Efficient schemes for decoupling and time reversal can be constructed from orthogonal arrays. Conditions...

This paper presents a technique for the control of the sideband radiations in timemodulated planar arrays. The proposed method is aimed at generating a desired pattern at the carrier frequency as well as reducing the power losses and the interferences related to the harmonic radiations. By acting on both the durations and the commutation instants of the time pulses controlling the element switc...

Coherent superposition of light from subwavelength sources is an attractive prospect for the manipulation of the direction, shape and polarization of optical beams. This phenomenon constitutes the basis of phased arrays, commonly used at microwave and radio frequencies. Here we propose a new concept for phased-array sources at infrared frequencies based on metamaterial nanocavities coupled to a...

This thesis presents a study of resonance dynamics in circuits of superconducting Josephson junctions. The Josephson junction is an intrinsically nonlinear device which, under certain conditions, can exhibit harmonic oscillations. This research begins with the dynamics of Josephson junctions connected in parallel with either periodic (ring geometry) or open-ended (row geometry) boundary conditi...