相关论文: Absorption and wavepackets in optically excited se…
We study coherent dynamics of tight-binding systems interacting with static and oscillating external fields. We consider Bloch oscillations and Wannier-Stark localization caused by dc fields, and compare these effects to dynamic…
We study the linear optical absorption of bulk semiconductors in the presence of a homogeneous constant (dc) electric field with an approach suitable for including excitonic effects while working with many-band models. The absorption…
Atomic wave packets loaded into a phase-modulated vertical optical-lattice potential exhibit a coherent delocalization dynamics arising from intraband transitions among Wannier-Stark levels. Wannier-Stark intraband transitions are here…
We present a time-domain analysis of carrier dynamics in a semiconductor superlattice with two minibands. Integration of the density-matrix equations of motion reveals a number of new features: (i) for certain values of the applied static…
A model for charge transport in undoped, photo-excited semiconductor superlattices, which includes the dependence of the electron-hole recombination on the electric field and on the photo-excitation intensity through the field-dependent…
We present a detailed study of the dynamics of electronic wavepackets in Fibonacci semiconductor superlattices, both in flat band conditions and subject to homogeneous electric fields perpendicular to the layers. Coherent propagation of…
Via the numerical analysis on the intraband dynamics of optically excited semiconductor superlattices, we find that time-integrated squared THz emission signals can be used for probing both dynamic localization and multi-photon resonance in…
We study a resistively shunted semiconductor superlattice subject to a high-frequency electric field. Using a balance equation approach that incorporates the influence of the electric circuit, we determine numerically a range of amplitude…
An ac field, tuned exactly to resonance with the Stark ladder in an ideal tight binding lattice under strong dc bias, counteracts Wannier-Stark localization and leads to the emergence of extended Floquet states. If there is random disorder,…
When the interface between a dielectric and a conducting liquid is excited by an oscillatory electric field, electrostatic Faraday waves can be induced. Here, we study the response of the interface to an AC electric field, which is…
The exciton absorption coefficient is determined analytically for a semiconductor superlattice in crossed electric and magnetic fields, for the magnetic field being parallel and the electric field being perpendicular to the superlattice…
We study super Bloch oscillations of ultracold atoms in a shaken lattice potential, subjected to a harmonically modulated mean-field interaction. Usually, any interaction leads to the decay of the wave packet and its super Bloch…
We study the evolution of a wave packet in a nonlinear Schr\"odinger lattice equation subject to a dc bias. In the absence of nonlinearity all normal modes are spatially localized giving rise to a Stark ladder with an equidistant eigenvalue…
We present a theoretical approach to study the effects of an ac-field applied to quantum dots with semi-spherical symmetry. Using the Floquet formalism for this periodically driven system, the time-dependent Hamiltonian in the effective…
The theoretical analysis of the ultrafast energy relaxation and transport phenomena in semiconductor superlattices is reviewed. In particular, we discuss the two equivalent quantum-mechanical pictures of Bloch oscillations and Wannier-Stark…
The coherent interband dynamics of optically excited two-dimensional lateral surface superlattices driven by an in-plane static electric field has been investigated. The linear absorption, the spectrally-resolved pump-probe four-wave mixing…
In this paper a coherent superposition of angular momentum states created by absorption of polarized light by molecules is analyzed. Attention is paid to the time evolution of wave packets representing spatial orientation of internuclear…
The continuum limit of a recently-proposed model for charge transport in resonant-tunneling semiconductor superlattices is analyzed. It is described by a nonlinear hyperbolic integrodifferential equation on a one-dimensional spatial…
A novel DC and AC driving configuration is proposed for semiconductor superlattices, in which the THz AC driving is provided by an intense bichromatic cw laser. The two components of the laser, usually in the visible light range, are near…
The effect of superimposed ac and dc electric fields on the formation of electroconvection and flexoelectric patterns in nematic liquid crystals was studied. For selected ac frequencies an extended standard model of the electro-hydrodynamic…