Related papers: Para-ortho transition of artificial H$_2$ molecule…
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…
We study the magnetic field induced singlet/triplet transition for two electrons in vertically coupled quantum dots by exact diagonalization of the Coulomb interaction. We identify the different mechanisms occurring in the transition,…
We study quantum states of electrons in magnetically doped quantum dots as a function of exchange coupling between electron and impurity spins, the strength of Coulomb interaction, confining potential, and the number of electrons. The…
The effect of orbital magnetism on the chemical bonding of lateral, two-dimensional artificial molecules is studied in the case of a 2e double quantum dot (artificial molecular hydrogen). It is found that a perpendicular magnetic field…
We present a correlated {\it ab initio} description of the paramagnetic phase of Tl$_2$Mn$_2$O$_7$, employing a combined local density approximation (LDA) with multiorbital dynamical mean field theory (DMFT) treatment. We show that the…
We analyse the effects of doping Holmium impurities into the full-Heusler ferromagnetic alloy Co$_2$MnSi. Experimental results, as well as theoretical calculations within Density Functional Theory in the "Local Density Approximation plus…
We analyze the transitions that a magnetic field provokes in the ground state of an artificial homonuclear diatomic molecule. For that purpose, we have performed numerical diagonalizations for a double quantum dot around the regime of…
Local structural measurements have been performed on hexagonal HoMnO3 in order to ascertain the specific changes in bond distances which accompany magnetic ordering transitions. The transition from paramagnetic to the antiferromagetic…
We report a comprehensive study of electronic-correlation effects in Manganese-based antiferromagnetic pnictides BaMn$_2$Pn$_2$ (Pn=P,As,Sb,Bi). Our density functional theory plus slave-spin mean-field simulations indicate that all the…
We study the artificial molecular states formed in laterally coupled double semiconductor nanorings by systems containing one, two and three electrons. An interplay of the interring tunneling and the electron-electron interaction is…
We study the low-temperature transport properties of the systems of parallel quantum dots described by the N-impurity Anderson model. We calculate the quasiparticle scattering phase shifts, spectral functions and correlations as a function…
We present a simple model to study the electron doped manganese perovskites. The model considers the competition between double exchange mechanism for itinerant electrons and antiferromagnetic superexchange interaction for localized…
Standard microscopic approach to magnetic orders is based on assuming a Heisenberg form for inter-atomic exchange interactions. These interactions are considered as a driving force for the ordering transition with magnetic moments serving…
We perform Hartree-Fock calculations to show that quantum dots (i.e. two dimensional systems of up to twenty interacting electrons in an external parabolic potential) undergo a gradual transition to a spin-polarized Wigner crystal with…
Coupled semiconductor quantum dots form artificial molecules where relevant energy scales controlling the interacting ground state can be easily tuned. By applying an external magnetic field it is possible to drive the system from a weak to…
We present a microscopic theory of the optical properties of self-assembled quantum dots doped with a single magnetic manganese (Mn) impurity and containing a controlled number of electrons. The single-particle electron and heavy-hole…
We consider ultracold matter of spin-2 atoms in optical lattices. We derive an effective Hamiltonian for the studies of spin ordering in Mott states and investigate hyperfine spin correlations. Particularly, we diagonalize the Hamiltonian…
We show that the effect of disorder on a Mott-Hubbard insulator of interacting electrons produces a quantum phase transition from an antiferromagnetic to a paramagnetic phase governed by a percolation of the singly occupied weakly…
While the phase diagrams of the one- and multi-orbital Hubbard model have been well studied, the physics of real Mott insulators is often much richer, material dependent, and poorly understood. In the prototype Mott insulator…
By using a multiscale approach based on first-principles density functional theory combined with atomistic spin dynamics, we investigate the electronic structure and magnetization dynamics of an inverse Heusler and a Heusler compound and…