Twofold Symmetry Observed in Bi$_{2}$Te$_{3}$/FeTe Interfacial Superconductor

Xinru Han; Hailang Qin; Tianluo Pan; Bin Guo; Kaige Shi; Zijin Huang; Jie Jiang; Hangyu Yin; Hongtao He; Fei Ye; Wei-Qiang Chen; Jia-Wei Mei; Gan Wang

arXiv · 2307.05904

Twofold Symmetry Observed in Bi$_{2}$Te$_{3}$/FeTe Interfacial Superconductor

Xinru Han·Hailang Qin·Tianluo Pan·Bin Guo·Kaige Shi·Zijin Huang·Jie Jiang·Hangyu Yin·Hongtao He·Fei Ye·Wei-Qiang Chen·Jia-Wei Mei·Gan Wang

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Abstract

Superconducting pairing symmetry are crucial in understanding the microscopic superconducting mechanism of a superconductor. Here we report the observation of a twofold superconducting gap symmetry in an interfacial superconductor Bi$_{2}$Te$_{3}$/FeTe, by employing quasiparticle interference (QPI) technique in scanning tunneling microscopy and macroscopic magnetoresistance measurements. The QPI patterns corresponding to energies inside and outside the gap reveal a clear anisotropic superconducting gap. Furthermore, both the in-plane angle-dependent magnetoresistance and in-plane upper critical field exhibit a clear twofold symmetry. This twofold symmetry align with the Te-Te direction in FeTe, which weakens the possible generation by bi-collinear antiferromagnetism order. Our finding provides key information in further understanding of the topological properties in Bi$_{2}$Te$_{3}$/FeTe superconducting system and propels further theoretical interests in the paring mechanism in the system.

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Xinru Han, Hailang Qin, Tianluo Pan, Bin Guo, Kaige Shi, Zijin Huang, Jie Jiang, Hangyu Yin, Hongtao He, Fei Ye, Wei-Qiang Chen, Jia-Wei Mei, Gan Wang. 2023-08-25. Twofold Symmetry Observed in Bi$_{2}$Te$_{3}$/FeTe Interfacial Superconductor. https://arxiv.org/abs/2307.05904

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