Related papers: Absorption and wavepackets in optically excited se…
We investigate theoretically the spatial dependence of the linear absorption spectra of single and coupled semiconductor quantum dots, where the strong three-dimensional quantum confinement leads to an overall enhancement of Coulomb…
Coherence phenomena in four-level atomic system, cyclicly driven by three coherent fields, are investigated thoroughly at zero and weak magnetic fields. Each strongly interacting atomic state is converted to a triplet due to a dynamical…
We study entanglement dynamics in the nearest-neighbour fermionic chain that is subjected to both DC and AC electric fields. The dynamics gives the well known Bloch oscillations in the DC field case provided that the system size is larger…
The time evolution of wavepackets in crystals in the presence of a homogeneous electric field is formulated in k-space in a numerically tractable form. The dynamics is governed by separate equations for the motion of the waveform in k-space…
We investigate a singly-charged quantum dot under a strong optical driving field by probing the system with a weak optical field. When the driving field is detuned from the trion transition, the probe absorption spectrum is shifted from the…
A new, exact method for calculating excitonic absorption in superlattices is described. It is used to obtain high resolution spectra showing the saddle point exciton feature near the top of the miniband. The evolution of this feature is…
We analyze the current dynamics of a superlattice Bloch oscillator under conditions where, in addition to the dc bias field causing a negative differential ac conductivity, a similarly strong ac field is present, at a frequency somewhat…
We study the motion of electrons in a single miniband of a semiconductor superlattice driven by THz electric field polarized along the growth direction. We work in the semiclassical balance-equation model, including different elastic and…
The optical absorption of a single spherical semiconductor quantum dot in an electrical field is studied taking into account the nonlocal coupling between the field of the light and the polarizability of the semiconductor. These nonlocal…
The equations-of-motion for the density matrix are derived in a multiband model to describe the response of semiconductors (bulk or quantum well structures) under optical excitation with arbitrary polarization. The multiband model used,…
We discuss a new mechanism of microwave absorption in s- and d-wave superconductors, which arises in the presence of a dc supercurrent in the system. It produces a contribution to the ac conductivity that is proportional to the inelastic…
We consider a model of an electron in a crystal moving under the influence of an external electric field: Schr\"{o}dinger's equation with a potential which is the sum of a periodic function and a general smooth function. We identify two…
We analyze the Wannier-Stark spectrum of a quantum particle in tilted two-dimensional lattices with the Bloch spectrum consisting of two subbands, which could be either separated by a finite gap or connected at the Dirac points. For…
Semiconductor nanoplatelets possess exceptional optical properties that make them promising candidates for next-generation optoelectronic applications. However, unlike quantum dots where absorption spectroscopy alone can determine both size…
The effect of an ac modulation on a 2-level or 3-level system is studied theoretically. The absorption spectrum is calculated by solving the optical Bloch equations and is interpreted by reference to the Floquet quasienergy spectrum. The…
The semiconductor Bloch equations for a two-band model including inter- and intraband excitation are used to study the nonlinear absorption of single and multiple light pulses by direct-gap semiconductors. For a consistent analysis the…
The electro-optical properties of most semiconductors and insulators of technological interest are dominated by the presence of electron-hole quasiparticles called excitons. The manipulation of these hydrogen-like quasi-particles in…
In a semiconductor superlattice with long scattering times, damping of Bloch oscillations due to scattering is so small that convective nonlinearities may compensate it and Bloch oscillations persist even in the hydrodynamic regime. In this…
A single band in a spatially periodic system splits into a series of quasienergy subbands under the action of DC--AC electric fields. These dynamic fractional Stark ladders should be observable in an investigation of optical absorption.
This study explores the linear and nonlinear optical absorption coefficients (OAC) and refractive index changes (RIC) in quantum dot and quantum antidot systems with a position-dependent variable effective mass. Significant contributions to…