The Rashba effect in Ge/Si0.15Ge0.85 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 effect, a threefold enhancement of the circular polarization degree of the direct transition is obtained by increasing the pump power over a 2 kW cm(-2) range. This marked variation reflects an efficient modulation of the spin population and is further supported by dedicated investigations of the indirect gap transition. This study demonstrates a viable strategy to engineer the spin-orbit Hamiltonian through contactless optical excitation and opens the way toward the electro-optical manipulation of spins in quantum devices based on group-IV heterostructures.
Rossi, S., Talamas Simola, E., Raimondo, M., Acciarri, M., Pedrini, J., Balocchi, A., et al. (2022). Optical Manipulation of the Rashba Effect in Germanium Quantum Wells. ADVANCED OPTICAL MATERIALS, 10(18) [10.1002/adom.202201082].
Optical Manipulation of the Rashba Effect in Germanium Quantum Wells
Talamas Simola E.;
2022-01-01
Abstract
The Rashba effect in Ge/Si0.15Ge0.85 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 effect, a threefold enhancement of the circular polarization degree of the direct transition is obtained by increasing the pump power over a 2 kW cm(-2) range. This marked variation reflects an efficient modulation of the spin population and is further supported by dedicated investigations of the indirect gap transition. This study demonstrates a viable strategy to engineer the spin-orbit Hamiltonian through contactless optical excitation and opens the way toward the electro-optical manipulation of spins in quantum devices based on group-IV heterostructures.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
