Mobile Kink Solitons in a Van der Waals Charge-Density-Wave Layer

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Kinks are stable, mobile defects studied in crystal deformations and DNA.
• Electronic properties of individual kinks remain largely unexplored.
• 1T-TaS2 is a correlated van der Waals insulator with domain walls.

Purpose of the Study:

• To investigate the electronic and topological properties of kinks in 1T-TaS2.
• To characterize the atomic structure and electronic states of these kinks.
• To explore the potential applications of these kinks in materials architectures.

Main Methods:

• Scanning tunneling microscopy (STM) was used to image kinks and antikinks.
• Atomic structures and in-gap electronic states were analyzed.
• The system's domain wall degeneracy was leveraged.

Main Results:

• Electronically and topologically distinct kinks were discovered along electronic domain walls in 1T-TaS2.
• Mobile kinks and antikinks were observed, trapped by pinning defects.
• The electronic states of kinks were mapped to Su-Schrieffer-Heeger solitons.
• A large number of distinct kinks emerged due to twelvefold domain wall degeneracy.

Conclusions:

• Individual kinks in 1T-TaS2 possess unique electronic and topological properties.
• The discovered kinks are mobile and can be imaged and characterized.
• The large degeneracy and robust nature of these kinks suggest potential for multilevel information handling in van der Waals materials.