Topological insulator homojunctions including magnetic layers: the example of n-p type ($n$-QLs Bi$_2$Se$_3$/Mn-Bi$_2$Se$_3$) heterostructures

Autor: Valiska, M., Warmuth, J., Michiardi, M., Vondracek, M., Ngankeu, A. S., Holy, V., Sechovsky, V., Springholz, G., Bianchi, M., Wiebe, J., Hofmann, P., Honolka, J.
Rok vydání: 2016
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1063/1.4954834
Popis: Homojunctions between Bi$_2$Se$_3$ and its Mn-doped phase are investigated as a sample geometry to study the influence of spin degrees of freedom on topological insulator properties. $n$ quintuple layers (QLs) of Bi$_2$Se$_3$ are grown ontop of Mn-doped Bi$_2$Se$_3$ by molecular beam epitaxy for $0\le n \le 30\,$QLs, allowing to unhamperedly monitor the development of electronic and topological properties by surface sensitive techniques like angle resolved photoemission spectroscopy. With increasing $n$, a Mn-induced gap at the Dirac point is gradually filled in an "hourglass" fashion to reestablish a topological surface state at $n \sim 9\,$QLs. Our results suggest a competition of upwards and downwards band bending effects due to the presence of an n-p type interface, which can be used to tailor topological and quantum well states independently.
Comment: 5 pages, 5 figures
Databáze: arXiv