We study the effects of layer thickness variations on the collective plasmon excitation modes of finite superlattices. Unlike other symmetry lowering mechanisms, thickness variation does not strongly localize the surface modes. We find that the reason for this insensitivity lies in the fact that the collective modes of a given finite structure must evolve continuously from the single-finite-sup...

Nanocrystals (NCs) exhibit unique size-dependent optical, electronic, and chemical properties. The ability to adjust properties by controlling size, shape, composition, crystallinity, and structure has led to a wide range of potential applications for NCs in areas such as optics, electronics, catalysis, magnetic storage, and biological labeling. Furthermore, NC assembly into 2D and 3D superlatt...

It is shown that the confined impurity state of a semiconductor quantum well develops into an excited impurity band in the case of a superlattice. This is studied by following theoretically the transition from a single to a multiple quantum well or superlattice by exactly diagonalizing the three-dimensional Hamiltonian for a quantum well system with random impurities. Intersubband absorption ex...

We demonstrate that specific surface superlattice gap solitons can be supported at an interface between a one-dimensional photonic superlattice and a uniform medium with saturable nonlinearity. The solitons are stable in the semi-infinite gap but do not exist in the first gap. With the decrease of the power, the solitons jump from the surface site to the next one, and they may continue the moti...

The motion of charge particles in a superlattice structure subject to the crossed magnetic and electric fields, both applied in the in-plane direction, is discussed with respect to the novel type of terahertz oscillations suggested recently, [M. Orlita, R. Grill, L. Smrčka, M. Zvára, Phys. Rev. B 74 (2006) 125312]. The effects of the finite size of the superlattice is considered in comparison w...

The dynamics of a charged particle in a superlattice under the action of an external electric field has been the subject of intense research [1–6]. Under different conditions, an electron is predicted to reveal a variety of time-dependent phenomena such as Bloch oscillations [1], Zener tunneling [2], self-induced transparency [3], miniband collapse [4], negative differential conductivity, and a...

We describe a limiting case when nonlinear dynamics of an ac-driven semiconductor superlattice in the miniband transport regime is governed by a periodically forced and damped pendulum. We find analytically the conditions for a transition to chaos, as well as the conditions for absence of chaosat any amplitude of ac drive. We also discuss fractional dc voltage states in a superlattice originati...

Soft x rays are generated when low-energy electron beams traverse a solid-state superlattice. We investigate the influence of x-ray absorption and electron scattering losses on the maximum power radiated, the required electron energy, and the optimum total thickness of the superlattice. We show that a moderate increase in the electron-beam energy compensates for the losses due to photoabsorptio...