Capping and gate control of anomalous Hall effect and hump structure in ultra-thin SrRuO₃ films

Ferromagnetism and exotic topological structures in SrRuO3 (SRO) induce sign-changing anomalous Hall effect (AHE). Recently, hump have been reported the resistivity of SRO thin films, especially ultra-thin regime. We investigate AHE structure films with an SrTiO3 (STO) capping layer ionic liquid gating. STO results sign changes modulation structure. In particular, is strongly modulated even vanishes STO-capped 4 unit cell films. addition, conductivity greatly enhanced restored ferromagnetism. also performed gating to modulate electric field at SRO/STO interface. Drastic are observed different gate voltages. Our study shows that as well can be controlled by tuning inversion symmetry