Stacking-Dependent Correlated Gap and Kondo Peak in the Heterophase Bilayer with Picometer-Level Interlayer Shift.

Liu, Liwei; Chen, Yaoyao; Liu, Zexuan; Song, Xuan; Yang, Han; Yang, Kai; Wang, Pengfei; Yang, Huixia et al. · ACS Nano · 2025

basic_science · Level V

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Abstract

Two-dimensional heterojunctions provide a versatile platform for exploring various quantum properties. Here, we create bilayer 1T/2H-NbSe<sub>2</sub> heterophase junctions and realize two types of stacking configurations with picometer-level lattice shifts. By high-resolution scanning tunneling microscopy/spectroscopy, we found that the electronic states are highly dependent on the stacking configurations of the 1T layer on the 2H one. Unexpectedly, a tiny shift between the two configurations (about 110 pm in the lateral direction and 30 pm in the vertical one) leads to a change from a correlated gap lattice into a Kondo peak lattice. Moreover, both of them show a spin-related pseudogap width of 2-3 meV close to the Fermi level, which splits under the external magnetic field. Our study demonstrates the important role of delicate stacking configurations on the many-body physics and spin-related phenomena in the heterophase junctions.