相关论文: Size effects on excitons in nano-rings

The magnetic field effects on excitons in an InAs nano-ring are studied theoretically. By numerically diagonalizing the effective-mass Hamiltonian of the problem, which can be separated into terms in centre-of-mass and relative coordinates,…

Quantum size effects for an exciton attached to a spherical quantum dot are calculated by a variational approach. The band line-ups are assumed to be type-II with finite offsets. The dependence of the exciton binding energy upon the dot…

We study the effect of magnetic field and geometric confinement on excitons confined to a quantum ring. We use analytical matrix elements of the Coulomb interaction and diagonalize numerically the effective-mass Hamiltonian of the problem.…

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…

The optical exciton Aharonov-Bohm effect, i. e. an oscillatory component in the energy of optically active (bright) states, is investigated in nanorings. It is shown that a small effective electron mass, strong confinement of the electron,…

The exciton ground state and excited state energies are calculated for a model system of an infinitely long cylindrical wire. The effective Coulomb potential between the electron and the hole is studied as function of the wire radius.…

The electronic structure of radially polarized excitons in structured nanorings is analyzed, with emphasis in the ground-state properties and their dependence under applied magnetic fields perpendicular to the ring plane. The electron-hole…

We study the Aharonov-Bohm effect for an exciton on a nano-ring using a 2D attractive fermionic Hubbard model. We extend previous results obtained for a 1D ring in which only azimuthal motion is considered, to a more general case of 2D…

We study theoretically the magnetic field effect on a neutral, but polarizable exciton confined in quantum-ring structures. For excitons with a nonzero dipole moment, a novel magnetic interference effect occurs: The ground state of an…

Size-quantization levels of an exciton in large nanocrystals is studied theoretically. For the nanocrystal size, $L$, much bigger than the Bohr radius, $a_B$, the level positions do not depend on $a_B$. The correction to the levels in a…

Transition energies and oscillator strengths of excitons in dependence on magnetic field are investigated in type I and II semiconductor nanorings. A slight deviation from circular (concentric) shape of the type II nanoring gives a better…

The exciton states in strained (In,Ga)As nanorings embedded in a GaAs matrix are computed. The strain distribution is extracted from the continuum mechanical model, and the exact diagonalization approach is employed to compute the exciton…

The absorption and emission spectra of silicon nanocrystals up to 1 nm diameter including geometry optimization and the many-body effects induced by the creation of an electron-hole pair have been calculated within a first-principles…

In this short paper we review a series of publications, some of which are our own, where various aspects of size effects were examined. By analyzing a series of examples we show that various intensive macroscopic characteristics of…

We show theoretically that the strong coupling of circularly polarized photons to an exciton in ring-like semiconductor nanostructures results in physical nonequivalence of clockwise and counterclockwise exciton rotations in the ring. As a…

Excitonic properties in the Kagome lattice system, which is produced by quantum wires on semiconductor surfaces, are investigated by using the exact diagonalization of a tight binding model. It is shown that due to the existence of flat…

The theory of exciton spectrum in multi-shell hexagonal semiconductor nanotube is developed within the effective masses and rectangular potentials approximations using the method of effective potential. It is shown that the exciton binding…

We present a simple analytic scheme for calculating the binding energy of excitons in semiconductors that takes full account of the existing anisotropy in the effective mass, as a complement to the qualitative treatment in most textbooks.…

The electronic structure and size-scaling of optoelectronic properties in cycloparaphenylene carbon nanorings are investigated using time-dependent density functional theory (TDDFT). The TDDFT calculations on these molecular nanostructures…

Theory of electronic and optical properties of exciton and bi-exciton complexes confined in CdSe spherical nanocrystals is presented. The electron and hole states are computed using atomistic $sp^3d^5s^*$ tight binding Hamiltonian including…