Related papers: Paramagnetic-diamagnetic interplay in quantum dots…
We study the conductance $g$ of an electron interferometer created in a two dimensional electron gas between a nanostructured contact and the depletion region induced by the charged tip of a scanning gate microscope. Using non-interacting…
In this dissertation we use sophisticated numerical methods in order to examine ground-state (GS) properties of two types of quantum systems with electron electron interactions: A quantum dot (QD) and a nano-wire. In the first half of the…
We report Electron Paramagnetic Resonance measurements on single crystalline and powder samples of Nd_0.5Ca_0.5MnO_3 across the charge-ordering transition at T_co=240 K down to the antiferromagnetic ordering transition at T_N = 140 K. The…
The physics of quantum dots is succinctly depicted by the {\it Universal Hamiltonian}, where only zero mode interactions are included. In the case where the latter involve charging and isotropic spin-exchange terms, this would lead to a…
Inelastic neutron scattering technique is employed to investigate the paramagnetic spin dynamics in a single crystalline sample of the magnetocaloric compound MnFe$_4$Si$_3$. In the investigated temperature range, 1.033$\times T_{C}$ to…
The $T$-dependence (2- 400 K) of the electron paramagnetic resonance (EPR), magnetic susceptibility, $\chi (T)$, and specific heat, $C_{v}(T)$, of the $normal$ antiferromagnetic (AFM) spinel ZnCr$_{2}$O$_{4}$ and the spin-glass (SG)…
Influence of resonant oscillating electromagnetic field on a single electron in coupled lateral quantum dots in the presence of phonon-induced relaxation and decoherence is investigated. Using symmetry arguments it is shown that spin and…
We use density-functional methods to study the effects of an external magnetic field on two-dimensional quantum dots with a rectangular hard-wall confining potential. The increasing magnetic field leads to spin polarization and formation of…
High-transition-temperature (high-Tc) superconductivity develops near antiferromagnetic phases, and it is possible that magnetic excitations contribute to the superconducting pairing mechanism. To assess the role of antiferromagnetism, it…
The hyperfine interaction of an electron with nuclei in the annealed self-assembled InAs/GaAs quantum dots is theoretically analyzed. For this purpose, the annealing process, and energy structure of the quantum dots are numerically modeled.…
We present a theoretical study of magnetic field driven spin transitions of electrons in coupled lateral quantum dot molecules. A detailed numerical study of spin phases of artificial molecules composed of two laterally coupled quantum dots…
Circulating orbital currents produced by the spin-orbit interaction for a single electron spin in a quantum dot are explicitly evaluated at zero magnetic field, along with their effect on the total magnetic moment (spin and orbital) of the…
Magnetic properties of the quasicrystal approximant Au$_{65}$Ga$_{21}$Tb$_{14}$ were investigated by the magnetization and the neutron diffraction experiments. The temperature dependences of the magnetic susceptibility and the magnetization…
In this work the intersubband electronic properties of two laterally coupled dome-shaped InAs/GaAs quantum dots were investigated. The envelope functions and eigenenergies were calculated as function of distance between the dots. The…
We discuss an exactly solvable model Hamiltonian for describing the interacting electron gas in a quantum dot. Results for a spherical square well confining potential are presented. The ground state is found to exhibit striking oscillations…
Highly accurate numerical results of phonon-induced two-electron spin relaxation in silicon double quantum dots are presented. The relaxation, enabled by spin-orbit coupling and the nuclei of $^{29}$Si (natural or purified abundance), are…
In this paper, we examine the effect of introducing a conical disclination on the thermal and optical properties of a two dimensional GaAs quantum dot in the presence of a uniform and constant magnetic field. In particular, our model…
The high-spectral-resolution spectroscopic studies of the energy gap evolution, supplemented with electronic, magnetic and structural characterization, show that the modification of the GaAs valence band caused by Mn incorporation occurs…
We investigate the spin of a multielectron GaAs quantum dot in a sequence of nine charge occupancies, by exchange coupling the multielectron dot to a neighboring two-electron double quantum dot. For all nine occupancies, we make use of a…
We present a theory of magnetotransport through a system of two coupled electronic orbitals, where the electron spin interacts with a (large) local magnetic moment via an exchange interaction. For the physical realization of such a set-up…