Related papers: Large nuclear Overhauser fields detected in vertic…
We investigate the dynamic nuclear polarization process by frequently injecting polarized electron spins into a quantum dot. Due to the suppression of the direct dipolar and indirect electron-mediated nuclear spin interactions, by the…
We use time-resolved detection of the Hanle effect and polarized photoluminescence with dark intervals to investigate the buildup and decay of the spin polarization of nuclei interacting with donor-bound electrons in $n$-doped GaAs. Strong…
We present a comprehensive examination of optical pumping of spins in individual GaAs quantum dots as we change the charge from positive to neutral to negative using a Schottky diode. We observe that photoluminescence polarization memory…
Electron-nuclear spin interactions by pulsed optical pumping have been found to polarize the nuclear spin system, leading to the nuclei building up an intrinsic magnetic field known as the Overhauser field. Studies have indicated an…
Using single-shot charge detection in a GaAs double quantum dot, we investigate spin relaxation time T_1 and readout visibility of a two-electron singlet-triplet qubit following single-electron dynamic nuclear polarization (DNP). For…
An all-optical scheme to polarize nuclear spins in a single quantum dot is analyzed. The hyperfine interaction with randomly oriented nuclear spins presents a fundamental limit for electron spin coherence in a quantum dot; by cooling the…
Nuclear spin polarization can be pumped into spin-blocked quantum dots by multiple Landau- Zener passages through singlet-triplet anticrossings. By numerical simulations of realistic systems including approximately $10^7$ nuclear spins…
We measure the dynamics of nuclear spins in a self-assembled quantum dot at a magnetic field of 5 Tesla and identify two distinct mechanisms responsible for the decay of the Overhauser field. We attribute a temperature-independent decay…
Single crystal silicon is an excellent system in which to explore dynamic nuclear polarization (DNP), as it exhibits a continuum of properties from metallic to insulating as a function of doping concentration and temperature. At low doping…
Conduction electrons are used to optically polarize, detect and manipulate nuclear spin in a (110) GaAs quantum well. Using optical Larmor magnetometry, we find that nuclear spin can be polarized along or against the applied magnetic field,…
Spin current perpendicular to the electric current is investigated around Landau level filling factor $\nu=3$ in a GaAs/AlGaAs two-dimensional electron system. Measurements of dynamic nuclear polarization in the vicinity of the edge of a…
Nuclear spin coherence and relaxation dynamics of all constituent isotopes of an n-doped CdTe/(Cd,Mg)Te quantum well structure are studied employing optically detected nuclear magnetic resonance. Using time-resolved pump-probe Faraday…
We demonstrate the extension of coherence between all four two-electron spin ground states of an InAs quantum dot molecule (QDM) via non-local suppression of nuclear spin fluctuations in both constituent quantum dots (QDs), while optically…
We applied the recently developed technique of force-detected nuclear magnetic resonance (NMR) to observe 71Ga, 69Ga, and 75As in GaAs. The nuclear spin-lattice relaxation time is 21$\pm$5 min for 69Ga at $\sim 5$ K and 4.6 Tesla. We have…
Photoluminescence polarization is experimentally studied for samples with (In,Ga)As/GaAs selfassembled quantum dots in transverse magnetic field (Hanle effect) under slow modulation of the excitation light polarization from fractions of Hz…
A method for high-field optically detected nuclear magnetic resonance (ODNMR) is developed sensitive to 10**8 nuclei. Nuclear spin transitions are induced using a radio frequency coil and detected through Faraday rotation spectroscopy.…
The nuclear spin fluctuations (NSF) as well as the dynamic nuclear polarization (DNP) and their effects on the electron spins in negatively charged (In,Ga)As/GaAs quantum dots have been studied by polarized pump-probe and photoluminescence…
We experimentally demonstrate a method for obtaining nuclear spin hyperpolarization, that is, polarization significantly in excess of that expected for a thermal equilibrium. By exploiting a modified Overhauser process, we obtain more than…
Measurements and modeling of electron spin transport and dynamics are used to characterize hyperfine interactions in Fe/GaAs devices with $n$-GaAs channels. Ga and As nuclei are polarized by electrically injected electron spins, and the…
In mesoscopic systems with spin-orbit coupling, spin-injection into quantum dots at zero magnetic field is expected under a wide range of conditions. However, up to now, a viable approach for experimentally identifying such injection has…