Synthesis of Superconductor-Topological Insulator Hybrid Nanoribbon Structures Piet Sch€ onherr and Fengyu Zhang Department of Physics, University of Oxford, Parks Road Oxford OX1 3PU, UK Vesna Srot and Peter van Aken Stuttgart Center for Electron Microscopy, Max Planck Institute for Solid State Research Heisenbergstr. 3, 70569 Stuttgart, Germany Thorsten Hesjedal * Department of Physics, University of Oxford Parks Road Oxford, OX1 3PU, UK thorsten.hesjedal@physics.ox.ac.uk Received 31 March 2017 Accepted 8 June 2017 Published 3 August 2017 Superconductors in proximity to topological insulators (TIs) have the potential to unlock exotic quantum phenomena, such as Majorana fermions. Quasi-one-dimensional structures are particu- larly suited to host these quantum states. Despite the growth of TI nanostructures being relatively straightforward, the in situ synthesis of superconductor-TI structures has been challenging. Here, we present a systematic study of the growth of the s-wave superconductor Sn on the TI Bi 2 Te 3 by physical vapor transport. If Sn does not enter the Bi 2 Te 3 lattice as a dopant, two types of structures are formed: Sn nanoparticles, that cover Bi 2 Te 3 plates and belts in a cloud-like shape, and thin Sn layers on Bi 2 Te 3 plates, that appear in puddle-like recessions. These heterostructures have potential applications as novel quantum devices. Keywords : Topological insulators; chemical vapor deposition; heterostructures; superconductors; electron microscopy. 1. Introduction Topological insulators (TIs) are band insulators with gapless, time-reversal symmetry protected to- pological surface states, which are not subject to backscattering by nonmagnetic impurities. 1 Their bandstructure is characterized by an odd number of Dirac cones residing in the bulk bandgap. 2 After the initial theoretical prediction, and the subsequent experimental demonstration of a two-dimensional * Corresponding author. This is an Open Access article published by World Scienti¯c Publishing Company. It is distributed under the terms of the Creative Commons Attribution 4.0 (CC-BY) License. Further distribution of this work is permitted, provided the original work is properly cited. 1750095-1 NANO: Brief Reports and Reviews Vol. 12, No. 8 (2017) 1750095 (7 pages) © The Author(s) DOI: 10.1142/S1793292017500953 NANO 2017.12. Downloaded from www.worldscientific.com by 168.151.130.52 on 09/22/17. For personal use only.