Related papers: Excitonic Effects in Quantum Wires
We present a theoretical approach to calculate the {\it local} absorption spectrum of excitons confined in a semiconductor nanostructure. Using the density-matrix formalism, we derive a microscopic expression for the non-local…
Single-layer quantum dot gate potential causes type-II band alignment, i.e. electrostatically confines holes and repels electrons, or vice versa. Hence, the confinement of excitons in gated type II quantum dots involves a delicate balance…
A novel approach for the control of exciton-exciton Coulomb coupling in semiconductor macroatoms/molecules is proposed. We show that by applying properly tailored external fields, we can induce ---or significantly reinforce--- excitonic…
The quantum states of an electron-hole pair in one-dimensional semiconductors under a static electric field are theoretically analyzed using a two-band model with on-site Coulomb interaction. In the absence of static field, the electron and…
We present a theoretical study of the energy spectrum of single electron and hole states in quantum dots of annular geometry under a high magnetic field along the ring axis in the frame of uncorrelated electron-hole theory. We predict the…
We theoretically investigate the Stark shift of the exciton goundstate in two vertically coupled quantum dots as a function of the interdot distance. The coupling is shown to enhance the tuneability of the linear optical properties,…
One-dimensional (1D) quantum wires provide a versatile platform for studying strong electron-electron interactions and collective excitations under confinement. Coulomb drag between 1D systems offers a powerful probe of Tomonaga-Luttinger…
We apply density functional theory, in the local density approximation, to a quasi-one-dimensional electron gas in order to quantify the effect of Coulomb and correlation effects in modulating, and therefore patterning, the charge density…
We study theoretically the optical properties of quantum tubes, one-dimensional semiconductor nanostructures where electrons and holes are confined to a cylindrical shell. In these structures, which bridge between 2D and 1D systems, the…
Electron interactions in and between wires become increasingly complex and important as circuits are scaled to nanometre sizes, or employ reduced-dimensional conductors like carbon nanotubes, nanowires and gated high mobility 2D electron…
A detailed analysis of the electro-optical response of single as well as coupled semiconductor quantum dots is presented. This is based on a realistic ---i.e., fully tridimensional--- description of Coulomb-correlated few-electron states,…
The energy levels and optical transitions of tetrahedral core/shell InP/ZnSe quantum dots (QDs) are investigated by means of multi-band k$\cdot$p theory. Despite the $\overline{T}_d$ symmetry relaxing spherical selection rules, the…
I. Introduction (Preface, Basic properties of semiconductor nanostructures). II. Theory of Coulomb-blockade oscillations (Periodicity of the oscillations, Amplitude and lineshape). III. Experiments on Coulomb-blockade oscillations (Quantum…
Single-electron tunneling through a zero-dimensional state in an asymmetric double-barrier resonant-tunneling structure is studied. The broadening of steps in the $I$--$V$ characteristics is found to strongly depend on the polarity of the…
Many-electron effects often dramatically modify the properties of reduced dimensional systems. We report calculations, based on an many-electron Green's function approach, of electron-hole interaction effects on the optical spectra of…
We consider theoretically the formation and stability of quasi-one dimensional many-body excitons in GaAs quantum wire structures under external photoexcitation conditions by solving the dynamically screened Bethe-Salpeter equation for…
Electron transport in a quantum wire with leads is investigated with actual Coulomb interaction taken into account. The latter includes both the direct interaction of electrons with each other and their interaction via the image charges…
We study theoretically the optical properties of an exciton in a two-dimensional ring threaded by a magnetic flux. We model the quantum ring by a confining potential that can be continuously tuned from strictly one-dimensional to truly…
Applying the novel exact-exchange (EXX) Kohn-Sham method within time-dependent density-functional theory, we obtained the optical absorption spectrum of bulk silicon in good agreement with experiments including excitonic features. Analysis…
We propose a quantum approach to "electron-hole exchange", better named electron-hole pair exchange, that makes use of the second quantization formalism to describe the problem in terms of Bloch-state electron operators. This approach…