Related papers: Optically monitored nuclear spin dynamics in indiv…
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 exciton spin memory in individual InAs/GaAs self-assembled quantum dots via optical alignment and conversion of exciton polarization in a magnetic field. Quasiresonant phonon-assisted excitation is successfully employed to…
A novel spin orientation mechanism - dynamic electron spin polarization has been recently suggested in Phys. Rev. Lett. $\mathbf{125}$, 156801 (2020). It takes place for unpolarized optical excitation in weak magnetic fields of the order of…
The spin diffusion concept provides a classical description of a purely quantum-mechanical evolution in inhomogeneously polarized many-body systems such as nuclear spin lattices. The central spin of a localized electron alters nuclear spin…
We present a quantum mechanical theory of optically induced dynamic nuclear polarization applicable to quantum dots and other interacting spin systems. The exact steady state of the optically driven coupled electron-nuclear system is…
The intensity and the giant circular polarization of edge luminescence in a longitudinal magnetic field have been measured in nitrogen alloys GaAsN under circularly polarized pumping. It has been found that these dependences are shifted…
Density-functional calculations using an exact exchange potential for a two-dimensional electron gas (2DEG) formed in a GaAs single quantum well predict the existence of a spin-polarized phase, when an excited subband becomes slightly…
In self assembled III-V semiconductor quantum dots, valence holes have longer spin coherence times than the conduction electrons, due to their weaker coupling to nuclear spin bath fluctuations. Prolonging hole spin stability relies on a…
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…
Time-resolved optical measurements of electron-spin dynamics in a (110) GaAs quantum well are used to study the consequences of a strongly anisotropic electron g-tensor, and the origin of previously discovered all-optical nuclear magnetic…
We show that detuned optical pulse trains with a modest spectral width can polarize nuclear spins in InAs quantum dots. The pulse bandwidth is large enough to excite a coherent superposition of both electron spin eigenstates in these…
The effect of nuclear spins in Fe/GaAs all-electrical spin-injection devices is investigated. At temperatures below 50 K, strong modifications of the non-local spin signal are found that are characteristic for hyperfine coupling between…
We demonstrate a new method for electrical manipulation of nuclear spins utilizing dynamic nuclear polarization induced by quantum Hall effect breakdown. Nuclear spins are polarized and detected through the hyperfine interaction between a…
We report the electrical induction and detection of dynamic nuclear polarization in the spin-blockade regime of double GaAs vertical quantum dots. The largest Overhauser field observed was about 4 Tesla, corresponding to a nuclear…
Magnetic noise of atomic nuclear spins is a major problem for solid state spin qubits. Highly-polarized nuclei would not only overcome this obstacle, but also make nuclear spins a useful quantum information resource. However, achieving…
Sub-picosecond ac spin current pulses are generated optically in GaAs bulk and quantum wells at room temperature and 90K through quantum interference between one-photon and two-photon absorptions driven by two phase-locked ultrafast laser…
We have studied polariton spin dynamics in a GaAs/AlGaAs microcavity by means of polarization- and time-resolved photoluminescence spectroscopy as a function of excitation density and normal mode splitting. The experiments reveal a novel…
We demonstrate the epitaxial growth of optical-quality electrically-gated III-V ferromagnetic quantum structures. Photoluminescence spectroscopy reveals that initially unpolarized photoexcited holes in a GaAs quantum well become…
Optical absorption of circularly polarized light is well known to yield an electron spin polarization in direct band gap semiconductors. We demonstrate that electron spins can even be generated with high efficiency by absorption of linearly…
Single lateral InGaAs quantum dot molecules have been embedded in a planar micro-cavity in order to increase the luminescence extraction efficiency. Using a combination of metal-organic vapor phase and molecular beam epitaxy samples could…