Related papers: Domain formation and self-sustained oscillations i…
Quantum Cascade Lasers (QCLs) are generally designed to avoid negative differential conductivity (NDC) in the vicinity of the operation point in order to prevent instabilities. We demonstrate, that the threshold condition is possible under…
A quantum cascade laser where the quantum wells in the active regions are replaced by quantum dots with their atom-like discrete energy levels is an interesting system to study novel features in optical spectroscopy. We study structures…
The ignition of Quantum Cascade Lasers can occur from a state of oscillating fie ld domains. Here, the interplay between lasing and the kinetics of traveling dom ain boundaries provides complex oscillation scenarios. We analyze our…
Stability control in laser is still an emerging field of research. In this paper the dynamics of External cavity semiconductor lasers (ECSLs) is widely studied applying the methods of chaos physics. The stability is analyzed through…
Using the effective mass and rectangular potential approximations, the theory of electron dynamic conductivity is developed for the plane multilayer resonance tunnel structure placed into a constant electric field within the model of open…
Quantum graphity offers the intriguing notion that space emerges in the low energy states of the spatial degrees of freedom of a dynamical lattice. Here we investigate metastable domain structures which are likely to exist in the low energy…
Quantum oscillations of nonlinear resistance are investigated in response to electric current and magnetic field applied perpendicular to single GaAs quantum wells with two populated subbands. At small magnetic fields current-induced…
The luminescence spectra of a quantum cascade laser in a strong magnetic field is influenced significantly by the presence of disorder (charged or neutral) in the system. An externally applied magnetic field parallel to the electron plane…
Oscillations of dissipative resistance of two-dimensional electrons in GaAs quantum wells are observed in response to an electric current I and a strong magnetic field applied perpendicular to the two-dimensional systems. Period of the…
We report on our study of the luminescence spectra of a quantum cascade laser in the presence of an external magnetic field tilted from the direction perpendicular to the electron plane. The effect of the tilted field is to allow novel…
Oscillons, extremely long-lived localized oscillations of a scalar field, are shown to be produced by evolving domain wall networks in quartic theory in two spatial dimensions. We study the oscillons in frequency space using the classical…
We discuss negative damping regimes in quantum nano-electromechanical systems formed by coupling a mechanical oscillator to a single-electron transistor (normal or superconducting). Using an analogy to a laser with a tunable atom-field…
Laser resonances play a crucial role in optical and quantum systems because the photons impact the stability and coherence of laser sources. While laser oscillations are typically stable and periodic, the presence of nonlinear effects can…
A discrete model is introduced to account for the time-periodic oscillations of the photocurrent in a superlattice observed by Kwok et al, in an undoped 40 period AlAs/GaAs superlattice. Basic ingredients are an effective negative…
We review the statics and dynamics of electric-field domains on doped superlattices within a discrete drift model. A complete analysis of the construction and stability of stationary field profiles having two domains is carried out. As a…
The self-assembled quantum dot with lens domain has rotational symmetry but it is intrinsically asymmetric when the electron moves perpendicularly to its circular base, {\it i. e.} along the rotational axis. To characterize this asymmetry,…
Oscillating fields can make domain patterns change into various types of structures. Numerical simulations show that concentric-ring domain patterns centered at a strong defect are observed under a rapidly oscillating field in some cases.…
A model of sequential resonant tunneling transport between two-dimensional subbands that takes into account explicitly elastic scattering is investigated. It is compared to transport measurements performed on quantum cascade lasers where…
Quantum cascade lasers are recognized as propitious candidates for future terahertz optoelectronics. Here we demonstrate several definite advantages of quantum dot cascade structures over quantum well devices, which suffer fundamental…
Electron tunneling between quantum Hall systems on the same two dimensional plane separated by a narrow barrier is studied. We show that in the limit where inelastic scattering time is much longer than the tunneling time, which can be…