Probing Broken Time-Reversal Symmetry in 2D Materials with Tailored-Light Photocurrent Generation – new publication in ACS Nano
In a recent study published in ACS Nano, FAU, LMU, and Technion researchers show that carefully tailored two-color laser fields can generate ultrafast bulk photogalvanic photocurrents that act as a sensitive probe of broken symmetries in 2D materials. They demonstrate in graphene that specific polarization angles and relative phases enforce a photocurrent selection rule that vanishes in time-reversal-symmetric systems, even though the combined light field still breaks other symmetries. Supported by experiment and ab initio simulations, the work further predicts that this forbidden signal becomes allowed in intrinsically time-reversal-symmetry-broken materials such as CrI₃, offering a background-free way to detect magnetism and Chern physics without external magnetic fields or circularly polarized light.
Read more at: https://pubs.acs.org/doi/full/10.1021/acsnano.5c17857