Spatially Resolved Circular Photogalvanic Effect (CPGE) in Cd₃As₂ Nanobelts

Cd₃As₂ is a material on its second rise to fame: its first in the late 20^th century following its classification as an inverted band semiconductor with unusually high mobility, and its second now as a gapless Dirac Semimetal. The combination of these two traits paints high promise in its application in fast broadband detector and spintronics technologies. Understanding spin-dependent transport in this system is paramount to utilizing its capabilities.

Using Scanning Photocurrent Microscopy (SPCM), we observed the Circular Photogalvanic Effect (CPGE) in field effect transistors exhibiting high mobility made out of Cd₃As₂ nanobelts, a phenomenon not yet reported in the literature for this system. This effect is local to the metal contact to Cd₃As₂ interface, and is mapped out at various temperatures and gate voltages. Possible mechanisms to explain the observed CPGE in Cd₃As₂such as Rashba splitting at the surfaces and interfaces will be explored.