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

期刊论文
出版模式：

开放获取
发表日期：

2024年9月24日

查看全文

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

摘要

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.