Related papers: Suppression of nuclear spin diffusion at a GaAs/Al…
This paper presents a study of electron spin dynamics in bulk GaAs at low temperatures for elevated optical excitation conditions. Our time-resolved Faraday rotation measurements yield sub-nanosecond electron spin dephasing-times over a…
The ability to discriminate between simultaneously occurring noise sources in the local environment of semiconductor InGaAs quantum dots, such as electric and magnetic field fluctuations, is key to understanding their respective dynamics…
Thermal measurements on a GaAs/AlGaAs heterostructure reveal that the state of the confined two-dimensional electrons dramatically affects the nuclear-spin diffusion near Landau level filling factor \nu=1. The experiments provide…
We investigate the intrinsic spin dynamics of electrons bound to Al impurities in bulk ZnO by optical spin noise spectroscopy. Spin noise spectroscopy enables us to investigate the longitudinal and transverse spin relaxation time with…
We develop an extended pump-probe Faraday rotation technique to study the submicrosecond electron spin dynamics with picosecond time resolution in a wide range of magnetic fields. The electron spin dephasing time $T_2^*$ and the…
The spin-flip tunneling rates are measured in GaAs-based double quantum dots by time-resolved charge detection. Such processes occur in the Pauli spin blockade regime with two electrons occupying the double quantum dot. Ways are presented…
We employ optical pump-probe spectroscopy to investigate the voltage dependence of spontaneous electron and nuclear spin polarizations in hybrid MnAs/n-GaAs and Fe/n-GaAs Schottky diodes. Through the hyperfine interaction, nuclear spin…
We utilize the kinetic spin Bloch equation approach to investigate the steady-state spin diffusion in $n$-type (111) GaAs quantum wells, where the in-plane components of the Dresselhaus spin-orbit coupling term and the Rashba term can be…
Early experiments on spin-blockaded double quantum dots revealed surprising robust, large-amplitude current oscillations in the presence of a static (dc) source-drain bias [see e.g. K. Ono, S. Tarucha, Phys. Rev. Lett. 92, 256803 (2004)].…
A quasi-classical theoretical description of polarization and relaxation of nuclear spins in a quantum dot with one resident electron is developed for arbitrary mechanisms of electron spin polarization. The dependence of the…
We report on the photoluminescence characterization of GaAs quantum dots embedded into AlGaAs nano-wires. Time integrated and time resolved photoluminescence measurements from both an array and a single quantum dot/nano-wire are reported.…
We present a comprehensive investigation of the electron-nuclear system of negatively charged InGaAs/GaAs self-assembled quantum dots under the influence of weak external magnetic fields (up to 2 mT). We demonstrate that, in contrast to…
We report on experiments in which a spin-polarized current is injected from a $GaMnAs$ ferromagnetic electrode into a $GaAs$ quantum well through an AlAs barrier. The resulting spin polarization in the GaAs well is detected by measuring how…
Dynamic nuclear polarization (DNP) is capable of boosting signals in nuclear magnetic resonance by orders of magnitude by creating out-of-equilibrium nuclear spin polarization. The diffusion of nuclear spin polarization in the vicinity of…
Heat capacity of the nuclear spin system (NSS) in GaAs-based microstructures has been shown to be much greater than expected from dipolar coupling between nuclei, thus limiting the efficiency of NSS cooling by adiabatic demagnetization. It…
The dynamics of a spin-1/2 particle coupled to a nuclear spin bath through an isotropic Heisenberg interaction is studied, as a model for the spin decoherence in quantum dots. The time-dependent polarization of the central spin is…
Using optical pulses of variable duration up to 80 ps, we report on spin coherence initialization and its subsequent detection in n-type singly-charged quantum dots, subject to a transverse magnetic field, by pump-probe techniques. We…
We demonstrate experimentally that a polarized nuclear spin modifies the dynamic behavior of a neighboring electronic spin. Specifically, an out-of-phase component appears in the electronic spin-echo signal. This component is proportional…
We demonstrate dynamical nuclear spin polarization in the absence of an external magnetic field, by resonant circularly polarized optical excitation of a single electron or hole charged quantum dot. Optical pumping of the electron spin…
We present experimental and theoretical results on hole-spin dynamics in bulk GaAs after ultrafast optical excitation. The experimental differential transmission are compared with a dynamical calculation of the momentum-resolved hole…