Engineering Domain Wall Electronic States in Strongly Correlated van der Waals Material of 1T-TaS2

Although a few physical methods were demonstrated for domain wall engineering in various electronic or ferroic materials with broken discrete symmetries, the direct control over the electronic properties of individual domain walls has been extremely limited. Here, we introduce a chemical method to tune the electronic property of domain walls in 1T tantalum disulfide. By using scanning tunneling microscopy and spectroscopy techniques, we find that indium adatoms on 1T-TaS2 have distinct behaviors on the domains with different bulk terminations. Moreover, the adatoms form their own chains along the edges of neighboring domains. The density functional theory calculations reveal a 1D Mott insulating state on a modified domain wall, resulting from the degenerated spin-polarized bands with electron doping from adsorbates and charge transfer from neighboring domains. This work suggests that chemical decoration by adsorbates can be widely used to tune local electronic states of domain walls and various 2D materials.

Automated summary

Despite limited control over the electronic properties of individual domain walls in various materials with broken symmetries, a chemical method using indium adatoms on 1T tantalum disulfide is introduced to tune the electronic properties of domain walls. Experimental observations show distinct behaviors of the adatoms on domains with different terminations, forming chains along the edges of neighboring domains. Density functional theory calculations reveal a 1D Mott insulating state on a modified domain wall, suggesting the potential for widely tuning local electronic states in domain walls and 2D materials through chemical decoration by adsorbates.