Regensburg 2016 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 84: Topological Insulators II
(Joint session of DS, HL, MA, O and TT organized by O)

TT 84.6: Vortrag

Freitag, 11. März 2016, 11:15–11:30, H15

Structural Study of Weak Topological Insulator Bi₁Te₁ Films on Si(111) grown by Molecular Beam Epitaxy — •Martin Lanius¹, Markus Eschbach¹, Ewa Mlynczak¹, Jens Kellner², Pika Gospodaric¹, Chengwang Niu¹, Elmar Neumann¹, Martina Luysberg³, Gregor Mussler¹, Lukasz Plucinski¹, Gustav Bihlmayer¹, Stefan Blügel¹, Markus Morgenstern², Claus Michael Schneider¹, and Detlev Grützmacher¹ — ¹Peter Grünberg Institut, Forschungszentrum Jülich, Germany — ²II. Institute of Physics B and JARA-FIT, RWTH Aachen University, Aachen, Germany — ³Ernst Ruska-Centre for Microscopy and Spectroskopy with Electrons, Forschungszentrum Jülich, Germany

We have studied the nucleation, growth process and structural composition of the weak topological insulator Bi₁Te₁ on Si(111) substrates by STM and STEM. Bi₁Te₁ is a superlattice of predicted 2D topological insulating materials, one bilayer Bi and two Bi₂Te₃ quintuple layers per unit cell. The van der Waals growth mode of Bi₁Te₁ shows smooth surfaces and a supressed twin domain density. The thin films from several nanometers thickness down to the nucleation regime have been grown by molecular beam epitaxy. STEM measurements of the grown films reveal a high crystalline perfection. Simulations and ARPES measurements show 2D surface states originating from spin-orbit coupling, depending in their structure on the surface termination. Furthermore we will demonstrate the ability to grow n-p heterostructures of n-doped Bi₁Te₁ with the p-doped strong TI Sb₂Te₃.