Optical tuning of the charge carrier type in the topological regime of InAs/GaSb quantum wells
Abstract
We study the optical tunability of the charge carrier type in InAs/GaSb double quantum wells with its type-II broken band alignment and inverted band structure. Under constant optical excitation, the majority charge carrier type switches from electron to hole. Within the majority charge carrier type transition, the coexisting minority charge carrier contribution indicates electron-hole hybridization with a non-trivial topological insulating phase. The optical tuning is attributed to the negative photoconductivity of antimonide materials in combination with a persistent charge carrier build-up of photo generated charges at the surface and substrate side of the device, respectively. Our study of the tuning of an InAs/GaSb double quantum well heterostructure reveals that an electro-optical switching is possible and paves the way to an optical control of the phase diagram of InAs/GaSb topological insulators.
Citation
Knebl , G , Pfeffer , P , Schmid , S , Kamp , M , Bastard , G , Batke , E , Worschech , L , Hartmann , F & Höfling , S 2018 , ' Optical tuning of the charge carrier type in the topological regime of InAs/GaSb quantum wells ' , Physical Review. B, Condensed matter and materials physics , vol. 98 , no. 4 , 041301(R) . https://doi.org/10.1103/PhysRevB.98.041301
Publication
Physical Review. B, Condensed matter and materials physics
Status
Peer reviewed
ISSN
1098-0121Type
Journal article
Description
The work was supported by the DFG (project Ka2318/5-1) and the Elite Network of Bavaria within the graduate program “Topological Insulators”.Collections
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