Moiré Superlattice-Induced Superconductivity in One-Unit-Cell FeTe

Hailang Qin; Xiaobin Chen; Bin Guo; Tianluo Pan; Meng Zhang; Bochao Xu; Junshu Chen; Hongtao He; Jiawei Mei; Weiqiang Chen; Fei Ye; Gan Wang

doi:10.1021/acs.nanolett.0c04048

Moiré Superlattice-Induced Superconductivity in One-Unit-Cell FeTe

Nano Lett. 2021 Feb 10;21(3):1327-1334. doi: 10.1021/acs.nanolett.0c04048. Epub 2021 Jan 29.

Authors

Hailang Qin¹, Xiaobin Chen², Bin Guo¹, Tianluo Pan³, Meng Zhang¹, Bochao Xu¹, Junshu Chen¹, Hongtao He¹, Jiawei Mei^{1

3}, Weiqiang Chen^{1

4}, Fei Ye^{1

3}, Gan Wang^{1

4}

Affiliations

¹ Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China.
² School of Science and State Key Laboratory on Tunable Laser Technology and Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System, Harbin Institute of Technology, Shenzhen 518055, China.
³ Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices, Southern University of Science and Technology, Shenzhen 518055, China.
⁴ Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.

PMID: 33513015
DOI: 10.1021/acs.nanolett.0c04048

Abstract

In this work, we demonstrate that the nonsuperconducting single-layer FeTe can become superconducting when its structure is properly tuned by epitaxially growing it on Bi₂Te₃ thin films. The properties of the single-layer FeTe deviate strongly from its bulk counterpart, as evidenced by the emergence of a large superconductivity gap (3.3 meV) and an apparent 8 × 2 superlattice (SL). Our first-principles calculations indicate that the 8 × 2 SL and the emergence of the novel superconducting phase are essentially the result of the structural change in FeTe due to the presence of the underlying Bi₂Te₃ layer. The structural change in FeTe likely suppresses the antiferromagnetic order in the FeTe and leads to superconductivity. Our work clearly demonstrates that moiré pattern engineering in a heterostructure is a reachable dimension for investigating novel materials and material properties.

Keywords: scanning tunneling spectroscopy (STS); single-layer FeTe/Bi2Te3; structural change; superconductivity.