Spatially dispersive helicity-dependent photocurrent in Dirac semimetal Cd3As2 nanobelts

Dirac semimetals (DSMs) have demonstrated many exotic properties, such as high carrier mobility, 3D quantum spin Hall effect, and topologically protected spin transport. However, their spin degeneracy has inhibited widespread applications in spintronics and quantum devices. Using a helicity-dependent photocurrent (HDPC), the authors demonstrate here spin generation in strain-free DSM Cd${}_{3}$As${}_{2}$ nanobelt field effect transistors at room temperature. The observed HDPC is attributed to spin-polarized Fermi arcs at the surface. This work provides key insights on light-controlled spin manipulation in Dirac materials.