2D Materials – Physics of
van der Waals [hetero]structures

Topological superconductivity and Majorana states in van der Waals heterostructures characterized by scanning probe microscopy

Principal investigator

Felix Lüpke, Forschungszentrum Jülich (PGI-3), f.luepke (at) fz-juelich.de [webpage]

Abstract

We will explore van der Waals (vdW) heterostructures of atomically thin topological insulators (TI) WTe₂ and (Bi_1-xSb_x)₂Te₃ on vdW superconductors (SC) NbSe₂ and FeTe_1-ySe_y in order to realize topological superconducting states via the superconducting proximity effect. By combination of topological superconducting states with magnetism, in form of a magnetic layer, magnetic clusters and in magnetic flux vortices, we will create Majorana states in the heterostructures. Samples will be studied by scanning tunneling microscopy (STM) at low temperatures to gain a deeper understanding of the underlying physics of topological superconductivity and Majorana states.

vdW heterostructures will be fabricated using a newly developed ‘dry-transfer flip technique’ [Lüpke et al., Nat. Phys. 16, 526 (2020)], as well as epitaxially grown by our collaborators. Samples will be transferred to the measurement chamber without air exposure, a critical aspect to maintain atomically clean surfaces.