- Suen, CT;
- Marković, I;
- Zonno, M;
- Heinsdorf, N;
- Zhdanovich, S;
- Jo, NH;
- Schmid, M;
- Hansmann, P;
- Puphal, P;
- Fürsich, K;
- Smit, S;
- Au-Yeung, C;
- Zimmermann, V;
- Zwartsenberg, B;
- Krautloher, M;
- Elfimov, IS;
- Koch, R;
- Gorovikov, S;
- Jozwiak, C;
- Bostwick, A;
- Franz, M;
- Rotenberg, Eli;
- Keimer, B;
- Damascelli, A
The Mott insulator Ca2RuO4 exhibits an insulator-to-metal transition induced by d.c. current. Despite the thorough examination of the structural changes associated with this transition, a comprehensive knowledge of the response of electronic degrees of freedom is still lacking. Here we demonstrate current-induced modifications of the electronic states of Ca2RuO4. Angle-resolved photoemission spectroscopy in conjunction with four-probe electrical transport (transport-ARPES) measurements reveal a clear reduction of the Mott gap and a modification in the dispersion of the Ru bands. Based on a free-energy analysis, we show that the current-induced phase is electronically distinct from the high-temperature zero-current metallic phase. Our results highlight strong interplay of lattice- and orbital-dependent electronic responses in the current-driven insulator-to-metal transition.