Related papers: Optically controlled spin-polarization memory effe…
We demonstrate negative polarization created by light-hole exciton excitation in g-factor engineered GaAs quantum wells measured by time-resolved Kerr rotation and polarization-resolved photoluminescence. This negative polarization is a…
We report on the resonant optical pumping of the |\pm1> spin states of a single Mn dopant in an InAs/GaAs quantum dot embedded itself in a charge tuneable device. The experiment relies on a "W" scheme of transitions reached when a suitable…
A trion magnetic polaron formed by the exchange interaction of a positively charged exciton (trion) with localized spins of Mn$^{2+}$ ions is found experimentally in a 4\,nm wide Cd$_{0.98}$Mn$_{0.02}$Te/Cd$_{0.78}$Mn$_{0.02}$Mg$_{0.2}$Te…
Under an in-plane magnetic field, the density of states of quasi two-dimensional carriers deviates from the occasionally stereotypic step-like form both quantitatively and qualitatively. For the first time, we study how this affects the…
We study experimentally the dependence of dynamic nuclear spin polarization on the power of non-resonant optical excitation in two types of individual neutral semiconductor quantum dots: InGaAs/GaAs and GaAs/AlGaAs. We show that the…
The role of nuclear spin fluctuations in the dynamic polarization of nuclear spins by electrons is investigated in (In,Ga)As quantum dots. The photoluminescence polarization under circularly polarized optical pumping in transverse magnetic…
We measured the polarization memory of excitonic and biexcitonic optical transitions from single quantum dots at either positive, negative or neutral charge states. Positive, negative and no circular or linear polarization memory was…
The discovery of ferromagnetism in Mn doped GaAs [1] has ignited interest in the development of semiconductor technologies based on electron spin and has led to several proof-of-concept spintronic devices [2-4]. A major hurdle for realistic…
It is shown that the Kerr rotation of spin-polarized electrons is modulated by the distance of the electrons from the sample surface. Time-resolved Kerr rotation of optically-excited spin-polarized electrons in the depletion layer of…
We have demonstrated by electroluminescence the injection of spin polarized electrons through Co/Al2O3/GaAs tunnel barrier into p-doped InAs/GaAs quantum dots embedded in a PIN GaAs light emitting diode. The spin relaxation processes in the…
We investigate the dynamic polarization of nuclear spins in a nominally undoped GaAs/Al$_{0.35}$Ga$_{0.65}$As quantum well using two complementary experimental approaches: time-resolved Kerr rotation and optical orientation measurements of…
The spin-dependent recombination (SDR) has been observed in GaAs_{1-x}N_{x} (x = 2.1, 2.7, 3.4%) at room temperature. It reveals itself in a decrease of the edge photoluminescence (PL) intensity by more than a factor of 3 when either the…
The magnetic order resulting from an indirect exchange between magnetic moments in the metallic phase of a Ga(1-x)Mn(x)As bilayered structure is studied "via" Monte Carlo simulation. The coupling mechanism involves a perturbative…
We report optical orientation experiments in individual, strain free GaAs quantum dots in AlGaAs grown by droplet epitaxy. Circularly polarized optical excitation yields strong circular polarization of the resulting photoluminescence at 4K.…
The coherent spin dynamics of resident carriers, electrons and holes, in semiconductor quantum structures is studied by periodical optical excitation using short laser pulses and in an external magnetic field. The generation and dephasing…
We study the optical orientation of electron spins in GaAs/AlGaAs quantum wells for excitation in the growth direction and for in-plane excitation. Time- and polarization-resolved photoluminescence excitation measurements show, for resonant…
The coupled spin and valley degrees of freedom in transition metal dichalcogenides (TMDs) are considered a promising platform for information processing. Here, we use a TMD heterostructure ${\text{MoS}_{2}-\text{MoSe}_{2}}$ to study optical…
The magnetic behavior of insulating doped diluted magnetic semiconductors (DMS) is characterized by the interaction of large collective spins known as bound magnetic polarons. Experimental measurements of the susceptibility of these…
The spin state of holes bound to Mn acceptors in GaMnAs is investigated by optical spectroscopy. Concentrations of Mn from 10^17 to 10^19 cm^-3 were studied as a function of magnetic field and temperature. The photoluminescence from…
We present a theoretical study of diluted magnetic semiconductors that treats the local sp-d exchange interaction J between the itinerant carriers and the Mn d electrons within a realistic band structure and goes beyond previous mean-field…