Related papers: Optically induced orbital polarization in bulk ger…
We have investigated optical orientation in the vicinity of the direct gap of bulk germanium. The electron spin polarization is studied via polarization-resolved photoluminescence excitation spectroscopy unfolding the interplay between…
Absorption of circularly polarized light in semiconductors is known to result in optical orientation of electron and hole spins. It has been shown here that in semiconductor quantum well structures spin orientation of carriers can be…
Light polarization can conveniently encode information. Yet, the ability to steer polarized optical fields is notably demanding but crucial to develop practical methods for data encryption and to gather fundamental insights into…
Optical spin orientation and depolarization phenomena in semiconductors are of overwhelming importance for the development of spin-optoelectronics. In this paper we employ Ge-based spin-photodiodes to investigate the room temperature…
The generation of an out-of-equilibrium population of spin-polarized carriers is a keystone process for quantum technologies and spintronics alike. It can be achieved through the so-called optical spin orientation by exciting the material…
Spin orientation of photoexcited carriers and their energy relaxation is investigated in bulk Ge by studying spin-polarized recombination across the direct band gap. The control over parameters such as doping and lattice temperature is…
We calculate circularly polarized luminescence emitted parallel (vertical emission) and perpendicular (edge emission) to the growth direction from a quantum well in a spin light-emitting diode (spin-LED) when either the holes or electrons…
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…
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…
To date, optical orientation of free-carrier spins and spin currents have been achieved by circularly polarized light, while the linearly polarized light has been used for optical alignment of electron momenta. Here we show that, in…
We demonstrate optical orientation in Ge/SiGe quantum wells and study their spin properties. The ultrafast electron transfer from the center of the Brillouin zone to its edge allows us to achieve high spin-polarization efficiencies and to…
We theoretically investigate the indirect optical injection of carriers and spins in bulk silicon, using an empirical pseudopotential description of electron states and an adiabatic bond charge model for phonon states. We identify the…
A quantum dot spin LED provides a test of carrier spin injection into a qubit, as well as a means of analyzing carrier spin injection in general and local spin polarization. The polarization of the observed light is, however, significantly…
The optical spin orientation effect in a GaAs/(Ga,Al)As quantum well containing a high-mobility 2D electron gas was found to be due to spin-polarized minority carriers, the holes. The observed oscillations of both the intensity and…
The Rashba effect in Ge/Si$_{0.15}$Ge$_{0.85}$ multiple quantum wells embedded in a p-i-n diode is studied through polarization and time-resolved photoluminescence. In addition to a sizeable redshift arising from the quantum-confined Stark…
Here we show the room temperature integrated detection of the helicity of photons with 1300 nm wavelength, via spin- photodiodes based on fully epitaxial Fe/MgO/Ge(001) heterostructures. These devices convert the photon helicity in a…
Optical orientation is a highly efficient tool for the generation of nonequilibrium spin polarization in semiconductors. Combined with spin-polarized transport it offers new functionalities for conventional electronic devices, such as pn…
We show that optically excited electrons by a circularly polarized light in a semiconductor with spin-orbit coupling subject to a weak electric field will carry a Hall current transverse to the electric field. This light induced Hall effect…
Free electrons moving in an optical standing wave field feel the ponderomotive potential, acting as a refractive-index medium in electron optics. Emerging technologies involving this potential have been proposed and realized in electron…
The injection of spin polarized electrons from ferromagnetic metals (Fe and Co) into gallium nitride (GaN) via scanning tunneling microscopy (STM) is demonstrated. Electrons from STM tips are injected into the semiconductor. Net circular…