Related papers: Optically Induced Magnetization of CdMnTe Self-Ass…
Understanding mechanisms of quantum ordering in strongly correlated systems remains a central challenge in condensed matter physics, with implications for designing novel quantum materials. Here, we investigate kinetic antiferromagnetism on…
Counterintuitive order-disorder phenomena emerging in antiferromagnetically coupled spin systems have been reported in various studies. Here we perform a systematic effective field theory analysis of two-dimensional bipartite quantum…
Electrically-induced electron spin polarization is imaged in n-type ZnSe epilayers using Kerr rotation spectroscopy. Despite no evidence for an electrically-induced internal magnetic field, current-induced in-plane spin polarization is…
Magnetic phenomena are in chemistry and condensed matter physics considered to be associated with low temperatures. That a magnetic state, or order, is stable below a critical temperature as well as becoming stronger the lower the…
A simple, single-color method for permanent marking of the position of individual self-assembled semiconductor Quantum Dots (QDs) at cryogenic temperatures is reported. The method combines in situ photolithography with standard…
We use ultrafast optical pulses and coherent techniques to create spin entangled states of non-interacting electrons bound to donors (at least three) and at least two Mn2+ ions in a CdTe quantum well. Our method, relying on the exchange…
Spin dynamics of a single electron and an exciton confined in CdTe/ZnTe quantum dot is investigated by polarization-resolved correlation spectroscopy. Spin memory effects extending over at least a few tens of nanoseconds have been directly…
A Dirac electron field is quantized in the background of a Dirac magnetic monopole, and the phenomenon of induced quantum numbers in this system is analyzed. We show that, in addition to electric charge, also squares of orbital angular…
The emission of circularly polarized light from a single quantum dot relies on the injection of carriers with well-defined spin polarization. Here we demonstrate single dot electroluminescence (EL) with a circular polarization degree up to…
We report on the optical spectroscopy of the spin of two magnetic atoms (Mn) embedded in an individual quantum dot interacting with either a single electron, a single exciton and single trion. As a result of their interaction to a common…
We investigate the electron and hole spin relaxation in an ensemble of self-assembled InAs/In$_{0.53}$Al$_{0.24}$Ga$_{0.23}$As/InP quantum dots with emission wavelengths around $1.5$~$\mu$m by pump-probe Faraday rotation spectroscopy.…
We report on polarization-resolved resonant photoluminescence (PL) spectroscopy of bright (spin-1) and dark (spin-2) excitons in colloidal CdSe nanocrystal quantum dots. Using high magnetic fields to 33 T, we resonantly excite (and…
The physics of strongly correlated fermions described by Hubbard or $t$-$J$ models in the underdoped regime -- relevant for high-temperature superconductivity in cuprate compounds -- remains a subject of ongoing debate. In particular, the…
Understanding quantum thermalization through entanglement build-up in isolated quantum systems addresses fundamental questions on how unitary dynamics connects to statistical physics. Here, we study the spin dynamics and approach towards…
We present a numerical treatment of a spin-orbital polaron model for Na_xCoO_2 at small hole concentration (0.7 < x < 1). We demonstrate how the polarons account for the peculiar magnetic properties of this layered compound: They explain…
We study the effect of a magnetic field on the conductance through a strongly interacting quantum dot by using the finite temperature extension of Wilson's numerical renormalization group method to dynamical quantities. The quantum dot has…
We discuss the possibility to generate, manipulate, and probe single spins in single-level quantum dots coupled to ferromagnetic leads. The spin-polarized currents flowing between dot and leads lead to a non-equilibrium spin accumulation,…
The electron doped manganite system, Bi0.125Ca0.875MnO3, exhibits large bulk magnetization of unknown origin. To select amongst possible magnetic ordering models, we have conducted temperature and magnetic field dependent small-angle…
We describe theoretically novel excitons in self-assembled quantum dots interacting with a two-dimensional electron gas in the wetting layer. In the presence of the Fermi sea, the optical lines become strongly voltage-dependent. If the…
The role of dipolar interactions and anisotropy are important to obtain, otherwise forbidden, ferromagnetic ordering at finite temperature for ions arranged in two-dimensional (2D) arrays (monolayers). Here we demonstrate that conventional…