In situ strain tuning of the metal-insulator-transition of Ca2RuO4 in angle-resolved photoemission experiments

DOI: 10.1038/s41467-018-06945-0

Authors: S. Ricco (University of Geneva) , M. Kim (CNRS) , A. Tamai (University of Geneva) , S. Mckeown Walker (University of Geneva) , F. Y. Bruno (University of Geneva) , I. Cucchi (University of Geneva) , E. Cappelli (University of Geneva) , C. Besnard (University of Geneva) , T. K. Kim (Diamond Light Source) , P. Dudin (Diamond Light Source) , M. Hoesch (Diamond Light Source) , M. J. Gutmann (ISIS Neutron and Muon Source) , A. Georges (ISIS Neutron and Muon Source) , R. S. Perry (University College London) , F. Baumberger (University of Geneva; Swiss Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Communications , VOL 9

State: Published (Approved)
Published: October 2018
Diamond Proposal Number(s): 17381

Abstract: Pressure plays a key role in the study of quantum materials. Its application in angle resolved photoemission (ARPES) studies, however, has so far been limited. Here, we report the evolution of the k-space electronic structure of bulk Ca2RuO4, lightly doped with Pr, under uniaxial strain. Using ultrathin plate-like crystals, we achieve uniaxial strain levels up to −4.1%, sufficient to suppress the insulating Mott phase and access the previously unexplored electronic structure of the metallic state at low temperature. ARPES experiments performed while tuning the uniaxial strain reveal that metallicity emerges from a marked redistribution of charge within the Ru t2g shell, accompanied by a sudden collapse of the spectral weight in the lower Hubbard band and the emergence of a well-defined Fermi surface which is devoid of pseudogaps. Our results highlight the profound roles of lattice energetics and of the multiorbital nature of Ca2RuO4 in this archetypal Mott transition and open new perspectives for spectroscopic measurements.

Journal Keywords: Electronic properties and materials; Phase transitions and critical phenomena

Subject Areas: Materials, Physics


Instruments: I05-ARPES

Other Facilities: ISIS

Added On: 06/11/2018 10:50

Documents:
s41467-018-06945-0.pdf

Discipline Tags:

Quantum Materials Hard condensed matter - electronic properties Physics Hard condensed matter - structures Materials Science Perovskites Metallurgy

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)