Hybrid Symmetry Epitaxy of the Superconducting Fe(Te,Se) Film on a Topological Insulator

Xiong Yao, Matthew Brahlek, Hee Taek Yi, Deepti Jain, Alessandro R. Mazza, Myung Geun Han, Seongshik Oh

Research output: Contribution to journalArticlepeer-review

Abstract

It is challenging to grow an epitaxial 4-fold compound superconductor (SC) on a 6-fold topological insulator (TI) platform due to the stringent lattice-matching requirement. Here, we demonstrate that Fe(Te,Se) can grow epitaxially on a TI (Bi2Te3) layer due to accidental, uniaxial lattice match, which is dubbed as "hybrid symmetry epitaxy". This new growth mode is critical to stabilizing robust superconductivity with TC as high as 13 K. Furthermore, the superconductivity in this FeTe1-xSex/Bi2Te3 system survives in the Te-rich phase with Se content as low as x = 0.03 but vanishes at Se content above x = 0.56, exhibiting a phase diagram that is quite different from that of the conventional Fe(Te,Se) systems. This unique heterostructure platform that can be formed in both TI-on-SC and SC-on-TI sequences opens a route to unprecedented topological heterostructures.

Original languageAmerican English
Pages (from-to)6518-6524
Number of pages7
JournalNano Letters
Volume21
Issue number15
DOIs
StatePublished - Aug 11 2021

ASJC Scopus subject areas

  • Bioengineering
  • General Chemistry
  • General Materials Science
  • Condensed Matter Physics
  • Mechanical Engineering

Keywords

  • Fe(Te,Se)/BiTe
  • Hybrid symmetry epitaxy
  • Superconductivity
  • Superconductor/topological insulator heterostructure
  • Uniaxial lattice match

Cite this