Unusual\nGeometric and Electronic Structures at Domain\nBoundaries in a Heterochiral Charge Density Wave Superlattice

Domain\nboundaries (DBs) in charge density wave (CDW) systems not\nonly are important for understanding the mechanism of how CDW interplays\nwith other quantum phases but also have potential for future CDW-based\nnanodevices. However, current research on DBs in CDW materials has\nbeen mainly limited to those between homochiral CDW domains, whereas\nDBs between heterochiral CDW domains, especially in the atomic layers,\nremain largely unexplored. Here, we have studied the geometric and\nelectronic states of heterochiral DBs in single-layer and bilayer\n1T-NbSe<sub>2</sub> using scanning tunneling microscopy/spectroscopy.\nWe observe the existence of diverse CDW configurations in a single\nheterochiral CDW DB with atomic resolution and reveal the corresponding\nelectronic states. In addition, interlayer stacking further enriches\nthe electronic properties of the DB. Our results offer deep insights\ninto the relationship between the detailed CDW nanostructures and\nelectronic behaviors, which has significant implications for DB engineering\nin strongly correlated CDW systems and related nanodevices.