Quantum size effect on charges and phonons ultrafast dynamics in atomically controlled nanolayers of topological insulators Bi₂Te₃.

ABSTRACT: Heralded as one of the key elements for next generation spintronics devices, topological insulators (TIs) are now step by step envisioned as nanodevices like charge-to-spin current conversion or as Dirac fermions based nanometer Schottky diode for example. However, reduced to few nanometers, TIs layers exhibit a profound modification of the electronic structure and the consequence of this quantum size effect on the fundamental carriers and phonons ultrafast dynamics has been poorly investigated so far. Here, thanks to a complete study of a set of high quality molecular beam epitaxy grown nanolayers, we report the existence of a critical thickness of around ~6 nm, below which a spectacular reduction of the carrier relaxation time by a factor of ten is found in comparison to bulk Bi₂

SUBMITTER: Weis M 

PROVIDER: S-EPMC5653873 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature