Camron Farhang

Abstract The magneto-optical Kerr effect (MOKE), the differential reflection of oppositely circularly polarized light, has traditionally been associated with relativistic spin-orbit coupling (SOC), which links a particle’s spin with its orbital motion. In ferromagnets, large MOKE signals arise from the combination of magnetization and SOC, while in certain coplanar antiferromagnets, SOC-induced Berry curvature enables MOKE despite zero net magnetization.

Abstract We report high resolution polar Kerr effect measurements on CsV3Sb5 single crystals in search of signatures of spontaneous time-reversal symmetry breaking below the charge-order transition at T*≈94K.

Abstract Recently, evidence has emerged in the topological superconductor Fe-chalcogenide FeTe1−xSex for time-reversal symmetry breaking (TRSB), the nature of which has strong implications on the Majorana zero modes (MZM) discovered in this system. It remains unclear, however, whether the TRSB resides in the topological surface state (TSS) or in the bulk, and whether it is due to an unconventional TRSB superconducting order parameter or an intertwined order.