Max Planck Institute for the Structure and Dynamics of Matter (MPSD) scientists have discovered a pioneering laser-driven approach to generate a topological state in graphene.
In topological materials, current actually flows orthogonally to an applied voltage. Topological transport is usually induced in materials by applying strong magnetic fields or by crafting compounds with strong spin-orbit coupling.
The team’s radically different approach consists of illuminating graphene with a strong, circularly polarized laser pulse, whose electric field drives electrons in loops. When the material is illuminated, it suddenly behaves like a topological material. It returns to its normal state once the pulse is gone. (Nature Physics)