Pressure-induced large anomalous Hall effects in a layered ferromagnet CrSiTe3

Abstract

Ferromagnetic semiconductor CrSiTe3 with a layered honeycomb structure is a promising candidate for the Chern insulator in a monolayer form. However, detecting its topological transport properties is challenging as Dirac nodes are located far above the Fermi level. High pressure, an effective route to control the electronic structure, provides an opportunity to measure its topological transport properties. We find that while CrSiTe3 maintains the honeycomb structure up to similar to 12 GPa, it undergoes an insulator-metal transition and a nearly concomitant increase of Curie temperature T-C from similar to 33 to similar to 85 K at P-1 similar to 6 GPa. Furthermore, the saturated magnetization M-s along the c-axis exhibits successive drops from M-s = 3 mu(B)/Cr at ambient pressure to similar to M-s/2 at P-1 and to similar to M-s/3 at 9.8 GPa. Notably, between P-1 and 13.5 GPa, the anomalous Hall conductivity sigma(AH)(xy) appears below T-C and sigma(AH)(xy) at 2 K exhibits a dome-like pressure evolution, reaching a maximum of similar to 67 Omega(-1)cm(-1), similar to 35% of e(2)/hc, at 10.4 GPa. These results suggest that large sigma(AH)(xy) arises from the intrinsic Berry curvature inherent to the band topology of the pressure-induced ferromagnetic metallic states.

Ferromagnetic semiconductor CrSiTe3 with a layered honeycomb structure is a promising candidate for the Chern insulator in a monolayer form. However, detecting its topological transport properties is challenging as Dirac nodes are located far above the Fermi level. High pressure, an effective route to control the electronic structure, provides an opportunity to measure its topological transport properties. We find that while CrSiTe3 maintains the honeycomb structure up to ~12 GPa, it undergoes an insulator‒metal transition and a nearly concomitant increase of Curie temperature TC from ~33 to ~85 K at P1 ~ 6 GPa. Furthermore, the saturated magnetization Ms along the c-axis exhibits successive drops from Ms = 3μB/Cr at ambient pressure to ~Ms/2 at P1 and to ~Ms/3 at 9.8 GPa. Notably, between P1 and 13.5 GPa, the anomalous Hall conductivity σAH xy appears below TC and σAH xy at 2 K exhibits a dome-like pressure evolution, reaching a maximum of 67 Ω1 cm1, ~ 35% of e2=hc, at 10.4 GPa. These results suggest that large σAH xy arises from the intrinsic Berry curvature inherent to the band topology of the pressure-induced ferromagnetic metallic states.