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arXiv · 2205.10134

Optical manipulation of the Rashba effect in germanium quantum wells

S. Rossi·E. Talamas Simola·M. Raimondo·M. Acciarri·J. Pedrini·A. Balocchi·X. Marie·G. Isella·F. Pezzoli
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Abstract

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 effect, a threefold enhancement of the circular polarization degree of the direct transition is obtained by increasing the pump power over a 2kW/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 towards the electro-optical manipulation of spins in quantum devices based on group-IV heterostructures.

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S. Rossi, E. Talamas Simola, M. Raimondo, M. Acciarri, J. Pedrini, A. Balocchi, X. Marie, G. Isella, F. Pezzoli. 2022-05-20. Optical manipulation of the Rashba effect in germanium quantum wells. https://doi.org/10.1002/adom.202201082

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