Electronic response of a Mott insulator at a current-induced insulator-to-metal transition

The Mott insulator Ca₂RuO₄ exhibits an insulator-to-metal transition induced by d.c. current. This study uses angle-resolved photoemission spectroscopy (ARPES) with four-probe electrical transport measurements to reveal current-induced modifications in Ca₂RuO₄'s electronic states, including a Mott gap reduction and altered Ru band dispersion. Free-energy analysis demonstrates that the current-induced phase is electronically distinct from the high-temperature zero-current metallic phase, highlighting the strong interplay between lattice and orbital-dependent electronic responses in the current-driven insulator-to-metal transition.

C. T. Suen, I. Marković, M. Zonno, N. Heinsdorf, S. Zhdanovich, N. H. Jo, M. Schmid, P. Hansmann, P. Puphal, K. Fürsich, S. Smit, C. Au-Yeung, V. Zimmermann, B. Zwartsenberg, M. Krautloher, I. S. Elfimov, R. Koch, S. Gorovikov, C. Jozwiak, A. Bostwick, M. Franz, Eli Rotenberg, B. Keimer, A. Damascelli