Single-edge switchable current flow in a charge density wave system

Boundary-induced electronic phenomena (edge-physics) play a crucial role in explaining the fundamental mechanism driving conductivity in exotic material systems where conventional band theory predicts a nonmetallic phase, advancing applicative quantum materials research. Yet despite a decade of scientific advancement in this field, limited layered material systems have been demonstrated to exhibit edge states, and the harnessing of such states for technological device applications remains challenging. In this talk, I will show experimental evidence for the emergence of confined-edge current flow rising from the Commensurate Charge Density Wave (CCDW) phase of the Van der Waals material 1T-TaS₂. Through the fabrication and conductance analysis of meso-scale 1T-TaS₂ crossbar devices we demonstrate the ability to toggle between high and low resistance states via anisotropic write currents. By spatially mapping the current density via scanning SQUID microscopy, we reveal the current density path in the low-resistance conduction state resides dominantly along the device edges. Surprisingly, the edge flow is confined to a single side of the device which selects a preferable edge and can be manipulated. This single confined edge current flow, which can be explained by CDW domain-wall or CDW single domain formation, raises many question regarding its nature and possible applications of confined current manipulation.