Related papers: Magnetic ordering in quantum dots: Open vs. closed…
We theoretically propose a new route to control magnetic and topological orders in a broad class of insulating magnets with a DC electric field. We show from the strong-coupling expansion that magnetic exchange interactions along the…
In magnetic topological insulators, quantized electronic transport is interwined with spontaneous magnetic ordering, as magnetization controls band gaps, hence band topology, through the exchange interaction. We show that considering the…
Using a recently developed variational quantum Monte Carlo method, magnetic properties of high-$T_{\rm C}$ superconductors are studied at zero temperature ($T$), by numerical simulations on the 2D t-J model. Our focus here is to explore the…
We study a new system in which electrons in two dimensions are confined by a non homogeneous magnetic field. The system consists of a heterostructure with on top of it a superconducting disk. We show that in this system electrons can be…
A two-dimensional array of quantum dots in a magnetic field is considered. The electrons in the quantum dots are described as unitary random matrix ensembles. The strength of the magnetic field is such that there is half a flux quantum per…
We study the effect of mesoscopic fluctuations on the magnitude of errors that can occur in exchange operations on quantum dot spin-qubits. Mid-size double quantum dots, with an odd number of electrons in the range of a few tens in each…
We present measurements of transport through two tunnel-coupled quantum dots of different sizes connected in series in a strong, variable, perpendicular magnetic field. Double dot conductance was measured both as a function of magnetic…
We develop a time dependent random matrix theory describing the influence of a time-dependent perturbation on mesoscopic conductance fluctuations in open quantum dots. The effect of external field is taken into account to all orders of…
Quantum dots in magnetic fields are studied within the current spin density functional formalism avoiding any spatial symmetry restrictions of the solutions. We find that the maximum density droplet reconstructs into states with broken…
Exchange interaction within a quantum dot strongly affects the transport through it in the Kondo regime. In a striking difference with the results of the conventional model, where this interaction is neglected, here the temperature and…
We study the nonequilibrium spin current through a quantum dot consisting of two localized spin-1/2 coupled to two ferromagnetic insulators. The influence of an intra-dot magnetic field and exchange coupling, different dot-reservoir…
Direction-dependent anisotropic exchange is a common feature of magnetic systems with strong spin-orbit coupling. Here we study the effect of such exchange upon macroscopic magnetic anisotropy for a face-centered-cubic model. By several…
An overview of recent studies on ferromagnetism in Cr- and Mn-based II-VI diluted magnetic semiconductors is presented emphasizing differences in underlying exchange mechanisms. Examples of manipulations with spin ordering by carrier…
We investigate the excitonic properties of a core-multishell semiconductor nanowire with type-II band mismatch, i.e. with spatially separated electrons and holes, under an external magnetic field. Our results demonstrate that, depending on…
We argue that recent neutron scattering measurements by Lake et. al. (Science 291, 1759 (2001)) of the spin excitation spectrum of LSCO in a magnetic field can be understood in terms of proximity to a phase with co-existing…
We find that mesoscopic conductance fluctuations in the quantum Hall regime in silicon MOSFETs display simple and striking patterns. The fluctuations fall into distinct groups which move along lines parallel to loci of integer filling…
We investigate the interplay of quantum fluctuations and magnetic anisotropies in metallic ferromagnets. Our central result is that fluctuations close to a quantum critical point can drive the moments to point along a magnetic hard axis. As…
We study the electronic states of core multi-shell semiconductor nanowires, including the effect of strong magnetic fields. We show that the multi-shell overgrowth of a free-standing nanowire, together with the prismatic symmetry of the…
The anomalous low-temperature behavior of the spontaneous magnetization of ordered arrays of In_{1-x}Mn_xAs quantum dots is discussed. It is shown that the experimental results can be well understood, within a mean field approximation,…
Carbon nanotubes continue to be model systems for studies of confinement and interactions. This is particularly true in the case of so-called "ultra-clean" carbon nanotube devices offering the study of quantum dots with extremely low…