Moiré superlattice modulations in single-unit-cell FeTe films grown on NbSe2 single crystals
Han-Bin Deng(邓翰宾), Yuan Li(李渊), Zili Feng(冯子力), Jian-Yu Guan(关剑宇), Xin Yu(于鑫), Xiong Huang(黄雄), Rui-Zhe Liu(刘睿哲), Chang-Jiang Zhu(朱长江), Limin Liu(刘立民), Ying-Kai Sun(孙英开), Xi-Liang Peng(彭锡亮), Shuai-Shuai Li(李帅帅), Xin Du(杜鑫), Zheng Wang(王铮), Rui Wu(武睿), Jia-Xin Yin(殷嘉鑫), You-Guo Shi(石友国), and Han-Qing Mao(毛寒青)
Chin. Phys. B, 2021, 30 (12):
Interface can be a fertile ground for exotic quantum states, including topological superconductivity, Majorana mode, fractal quantum Hall effect, unconventional superconductivity, Mott insulator, etc. Here we grow single-unit-cell (1UC) FeTe film on NbSe2 single crystal by molecular beam epitaxy (MBE) and investigate the film in-situ with a home-made cryogenic scanning tunneling microscopy (STM) and non-contact atomic force microscopy (AFM) combined system. We find different stripe-like superlattice modulations on grown FeTe film with different misorientation angles with respect to NbSe2 substrate. We show that these stripe-like superlattice modulations can be understood as moiré pattern forming between FeTe film and NbSe2 substrate. Our results indicate that the interface between FeTe and NbSe2 is atomically sharp. By STM-AFM combined measurement, we suggest that the moiré superlattice modulations have an electronic origin when the misorientation angle is relatively small (≤ 3°) and have structural relaxation when the misorientation angle is relatively large (≥ 10°).