Controlling a Van Hove singularity and Fermi surface topology at a complex oxide heterostructure interface

Journal Article · 03 December 2019 · Nature Communications

DOI: https://doi.org/10.1038/s41467-019-13046-z · OSTI ID:1619601

Mori, Ryo ; Marshall, Patrick B.; Ahadi, Kaveh; Denlinger, Jonathan D.; Stemmer, Susanne; Lanzara, Alessandra

Abstract The emergence of saddle-point Van Hove singularities (VHSs) in the density of states, accompanied by a change in Fermi surface topology, Lifshitz transition, constitutes an ideal ground for the emergence of different electronic phenomena, such as superconductivity, pseudo-gap, magnetism, and density waves. However, in most materials the Fermi level, $$$${E}_{{\rm{F}}}$$$$ $E_F$ , is too far from the VHS where the change of electronic topology takes place, making it difficult to reach with standard chemical doping or gating techniques. Here, we demonstrate that this scenario can be realized at the interface between a Mott insulator and a band insulator as a result of quantum confinement and correlation enhancement, and easily tuned by fine control of layer thickness and orbital occupancy. These results provide a tunable pathway for Fermi surface topology and VHS engineering of electronic phases.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: Funai Foundation for Information Technology; Gordon and Betty Moore Foundation (GBMF); National Science Foundation (NSF); USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Scientific User Facilities Division
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1619601
• Journal Information: Nature Communications, Journal Name: Nature Communications Journal Issue: 1 Vol. 10; ISSN 2041-1723
• Publisher: Nature Publishing GroupCopyright Statement
• Country of Publication: United Kingdom
• Language: English