CrGeTe3 is an electronically insulating van der Waals ferromagnet with a curie temperature of ~67K. It has been previously shown that under application of hydrostatic pressure CrGeTe3 undergoes a metal-insulator transition accompanied by a significant increase in its Curie temperature as pressure is applied.
It was proposed that the enhanced ferromagnetism and the metallicity are linked due to the emergence of ferromagnetic RKKY interaction at the metal-insulator transition. In this talk, I will cover our recent experiments which further investigate this link and attempt to utilize it to optically enhance the ferromagnetic properties of CrGeTe3. First, we probe the scattering mechanisms responsible for the anomalous hall effect at high hydrostatic pressure and show that significant Berry curvature appears when at the metal-insulator transition and exhibits a dome-like shape as a function of pressure. In the second experiment, we attempt to optically enhance the RKKY interaction by injecting photo carriers to the conduction band of CrGeTe3 when it is in its insulating phase. Surprisingly, under these conditions, we observe evidence for time-reversal symmetry breaking even at temperatures three times higher than the Curie temperature. | 
