- Li, Zhuolu;
- Shen, Shengchun;
- Tian, Zijun;
- Hwangbo, Kyle;
- Wang, Meng;
- Wang, Yujia;
- Bartram, F Michael;
- He, Liqun;
- Lyu, Yingjie;
- Dong, Yongqi;
- Wan, Gang;
- Li, Haobo;
- Lu, Nianpeng;
- Zang, Jiadong;
- Zhou, Hua;
- Arenholz, Elke;
- He, Qing;
- Yang, Luyi;
- Luo, Weidong;
- Yu, Pu
Ionic substitution forms an essential pathway to manipulate the structural phase, carrier density and crystalline symmetry of materials via ion-electron-lattice coupling, leading to a rich spectrum of electronic states in strongly correlated systems. Using the ferromagnetic metal SrRuO3 as a model system, we demonstrate an efficient and reversible control of both structural and electronic phase transformations through the electric-field controlled proton evolution with ionic liquid gating. The insertion of protons results in a large structural expansion and increased carrier density, leading to an exotic ferromagnetic to paramagnetic phase transition. Importantly, we reveal a novel protonated compound of HSrRuO3 with paramagnetic metallic as ground state. We observe a topological Hall effect at the boundary of the phase transition due to the proton concentration gradient across the film-depth. We envision that electric-field controlled protonation opens up a pathway to explore novel electronic states and material functionalities in protonated material systems.