Faculty/School:Ernst Ruska-Centre, Research Center Juelich
Publisher:ACS Nano
Description of Publication:The proximity effect at an s-wave superconductor (S) and a topological insulator (TI) provides a promising platform to create Majorana zero modes in artificially designed heterostructures. However, structural and chemical issues pertinent to such interfaces are poorly explored so far. Here, we report the discovery of Pd diffusion induced interfacial polarization in Pd1+x(Bi0.4Te0.6)2 and Pd-intercalated Bi2Te3 by using atomic-resolution scanning transmission electron microscopy. Our quantitative image analysis reveals that nanoscale lattice strain and QL polarity synergistically suppress and promote the Pd diffusion at the normal and parallel interfaces. First-principles calculations unveil that the superconductivity of xPBT phase and topological nature of Pd-intercalated Bi2Te3 phase are robust against the broken inversion symmetry. These findings point out the necessity of considering coexistence of electric polarization with superconductivity and topology in such S-TI systems.
