Dynamic topological domain walls driven by lithium intercalation in graphene

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Devices

Background:

• Stacking engineering in van der Waals (vdW) materials is crucial for controlling topological electronic phases.
• Atomic intercalation offers a non-technical method to precisely modify vdW material stacking structures.

Purpose of the Study:

• To investigate the effects of lithium intercalation on topological domain wall (TDW) dynamics in a graphene/SiC system.
• To explore the potential of atomic intercalation for controlling stacking order and topological electronic phases.

Main Methods:

• In situ aberration-corrected low-energy electron microscopy was employed to observe intercalation dynamics.
• Theoretical modeling was used in conjunction with experimental observations.
• Sequential and selective lithium intercalation was analyzed at atomic resolution.

Main Results:

• Lithium intercalation initiated at topological crossing points (AA stacking) and selectively spread to AB stacking domains.
• Intercalation locally altered domain stacking order to AA, influencing neighboring TDW stacking orders.
• Continuous intercalation led to the evolution of the entire topological structure network, revealing moving TDWs.

Conclusions:

• Atomic intercalation provides a pathway to dynamically control stacking structures and topological electronic phases in vdW materials.
• Moving TDWs, protected by stacking topology, were observed and characterized.
• This research lays the groundwork for developing novel intercalation-driven vdW electronic devices.