Understanding the physical and chemical processes at the interface of metals and topological insulators is crucial for developing the next generation of topological quantum devices. Here we report the discovery of robust superconductivity in Pd/Bi2Se3 bilayers fabricated by sputtering Pd on the surface of Bi2Se3. Through transmission electron microscopy measurements, we identify that the observed interfacial superconductivity originates from the diffusion of Pd into Bi2Se3. In the diffusion region, Pd chemically reacts with Bi2Se3 and forms a layer of PdBiSe, a known su-perconductor with a bulk transition temperature of 1.5 K. Our work provides a method for in-troducing superconductivity into Bi2Se3, laying the foundation for developing sophisticated Bi2Se3-based topological devices.
@article{arxiv.2412.00701,
title = {Superconductivity at Pd/Bi$_2$Se$_3$ Interfaces Due to Self-Formed PdBiSe Interlayers},
author = {Kaixuan Fan and Ze Hua and Siyao Gu and Peng Zhu and Guangtong Liu and Hechen Ren and Ruiwen Shao and Zhiwei Wang and Li Lu and Fan Yang},
journal= {arXiv preprint arXiv:2412.00701},
year = {2026}
}