TY  - EJOUR
AU  - Wei, Xian-Kui
AU  - Jalil, Abdur Rehman
AU  - Rüßmann, Philipp
AU  - Ando, Yoichi
AU  - Grützmacher, Detlev
AU  - Blügel, Stefan
AU  - Mayer, Joachim
TI  - Atomic diffusion-induced polarization and superconductivity in topological insulator-based heterostructures
PB  - arXiv
M1  - FZJ-2023-05764
PY  - 2023
AB  - The proximity effect at a highly transparent interface of 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 polarization at interfaces between superconductive Pd$_{1+x}$(Bi$_{0.4}$Te$_{0.6}$)$_2$ (xPBT, $0\le x \le 1$) and Pd-intercalated Bi$_2$Te$_3$ 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, formed between Te-Pd-Bi triple layers (TLs) and Te-Bi-Te-Bi-Te quintuple layers (QLs), respectively. Further, our first-principles calculations unveil that the superconductivity of xPBT phase and topological nature of Pd-intercalated Bi$_2$Te$_3$ 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.
KW  - Materials Science (cond-mat.mtrl-sci) (Other)
KW  - Superconductivity (cond-mat.supr-con) (Other)
KW  - FOS: Physical sciences (Other)
LB  - PUB:(DE-HGF)25
DO  - DOI:10.48550/ARXIV.2311.16590
UR  - https://juser.fz-juelich.de/record/1019943
ER  -