Investigation of Electric Field Induced Topological Magnons in MnPSe₃

Topologically insulated surface magnons are of immense interest because of the prospective of their application in proposed highly efficient, versatile topological spin wave devices. We predict an electric field induced topological order transition for MnPSe₃ below its Neel temperature in which a magnon gap opens and enables topologically insulated surface magnon modes. Flip chip processing of few layered MnPSe₃ nanoflakes on nano-thickness platinum strips is used to create non-local spin transport devices. A red shift of the optical band edge due to the Franz-Keldysh effect is observed using spatially resolved photocurrent spectroscopy measurements in laterally biased devices at room temperature, which allows quantification of the lateral electric field. We will discuss the results of such measurements as a function of temperature and applied lateral electric field in relation to the topological transition and the associated nonlocal spin transport signals emerging with bias.