Spin Polarization of Carriers in InGaAs Self-Assembled Quantum Rings Inserted in GaAs-AlGaAs Resonant Tunneling Devices

Abstract

In this work, we have investigated transport and polarization resolved photoluminescence (PL) of n-type GaAs-AlGaAs resonant tunneling diodes (RTDs) containing a layer of InGaAs self-assembled quantum rings (QRs) in the quantum well (QW). All measurements were performed under applied voltage, magnetic fields up to 15 T and using linearly polarized laser excitation. It was observed that the QRs' PL intensity and the circular polarization degree (CPD) oscillate periodically with applied voltage under high magnetic fields at 2 K. Our results demonstrate an effective voltage control of the optical and spin properties of InGaAs QRs inserted into RTDs.

Modeling of anisotropic properties of double quantum rings by the terahertz laser field

“…The tunneling effect in QRs is responsible for the intermediate-band in the coupled array of QRs 6 . It was used as an additional path for the electron transitions to the continuum to enhance the photocurrents for solar cell applications 7 and resonant tunneling devices as well 8 . Besides, doubly-connected ring-like geometry is currently used to form materials with unique properties: in quantum dot-ring nanostructures (a QD surrounded by a QR) 9 , 10 spin relaxation times, optical absorption and conducting properties are highly tunable by means of the confinement 11 , 12 ; electrochemical performance and structure evolution of core-shell nano-ring α -Fe 2 O 3 @ Carbon anodes for lithium-ion batteries 13 ; the electrical properties of a p-type semiconductor can be mimicked by a metamaterial solely made up of an n-type semiconductor ZnO rings 14 ; etc.…”