Recent Publications

Topological superconductivity in a phase-controlled Josephson junction

Abstract

Topological superconductors can support localized Majorana states at their boundaries. These quasi-particle excitations obey non-Abelian statistics that can be used to encode and manipulate quantum information in a topologically protected manner. Although signatures of Majorana bound states have been observed in one-dimensional systems, there is an ongoing effort to find alternative platforms that do not require fine-tuning of parameters and can be easily scaled to large numbers of states. Here we present an experimental approach towards a two-dimensional architecture of Majorana bound states. [...]

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Bismuthene on a SiC substrate: A candidate for a high-temperature quantum spin Hall material

Abstract

Quantum spin Hall (QSH) materials promise revolutionary device applications based on dissipationless propagation of spin currents. They are two-dimensional (2D) representatives of the family of topological insulators, which exhibit conduction channels at their edges inherently protected against scattering. [...]

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Interaction-induced helical gaps in nanowires

Abstract

Spin–momentum locking in a semiconductor device with strong spin–orbit coupling (SOC) is thought to be an important prerequisite for the formation of Majorana bound states. Such a helical state is predicted in one-dimensional (1D) nanowires subject to strong Rashba SOC and spin-mixing—its hallmark being a characteristic re-entrant behaviour in the conductance. Here, we report direct experimental observations [...]

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Spin-polarized midgap states in TCIs

Abstract

Topological crystalline insulators are materials in which the crystalline symmetry leads to topologically protected surface states with a chiral spin texture, rendering them potential candidates for spintronics applications. Using scanning tunneling spectroscopy, we uncover the existence of one-dimensional (1D) midgap states at odd-atomic surface step edges of the three-dimensional topological crystalline insulator (Pb,Sn)Se. [...]

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