Discovery of Room-Temperature Charge Order in a Correlated Kagome Superconductor LaRu<sub>3</sub>Si<sub>2</sub>

ORAL

Abstract

The kagome lattice is an intriguing and rich platform for discovering, tuning and understanding the diverse phases of quantum matter. The possibility to access correlated order at room temperature has been extensively studied, but has remained elusive. Here we utilize single crystal X-ray diffraction to discover charge order beyond room-temperature in the prototypical kagome superconductor La(Ru1-xFex)3Si2 (x = 0, 0.01, 0.05) [1]. Namely, it is found that charge order related to out-of-plane displacements of Ru atoms appears below TCO-I = 400 K. The appearance of a second charge ordered phase, competing with the primary one, is found at lower temperatures TCO-II = 80-170 K. Furthermore, first principles calculations show that in LaRu3Si2, both the kagome flat band and the van Hove point with strong electron-electron interaction, formed by the Ru-dz2 orbitals, are very close to the Fermi energy. Our results present the first example of a charge ordered state at or above room temperature in the correlated kagome lattice and classifies the system LaRu3Si2 as the superconductor with the highest charge ordering temperature. Our finding introduces a new platform for the exploration of the correlation-driven room temperature phases (e.g., superconductivity, collosal magnetoresistance, etc.) in layered quantum materials, and also promotes the practical development of charge-order-related technology and devices.

[1] I. Plokhikh, C. Mielke III et al. arXiv:2309.09255 (2023).

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Publication: https://arxiv.org/abs/2309.09255
arXiv:2309.09255

Presenters

  • Charles Mielke

    • Paul Scherrer Institute

Authors

  • Charles Mielke

    • Paul Scherrer Institute

  • Igor Plokhikh

    • Paul Scherrer Institut
    • Paul Scherrer Institute

  • H Nakamura

    • Institute for Solid State Physics (ISSP), University of Tokyo

  • Vaclav Petricek

    • Czech Academy of Sciences
    • Institute of Physics, Academy of Science of the Czech Republic

  • Vahid Sazgari

    • Paul Scherrer Institut
    • Paul Scherrer Institute

  • Julia Küspert

    • University of Zurich

  • Izabela Biało

    • University of Zurich

  • Soohyeon Shin

    • Paul Scherrer Institut

  • Oleh Ivashko

    • DESY
    • Deutsches Elektronen-Synchrotron

  • Martin von Zimmermann

    • DESY
    • Deutsches Elektronen-Synchrotron

  • Marisa Medarde

    • Paul Scherrer Institut
    • PSI
    • Paul Scherrer Institute

  • Alex Amato

    • Paul Scherrer Institut
    • Paul Scherrer Institute

  • Rustem Khasanov

    • Paul Scherrer Institut
    • PSI
    • Paul Scherrer Institute

  • Hubertus Luetkens

    • Paul Scherrer Institut
    • Paul Scherrer Institute
    • Paul Scherrer Institut Forschungsstrasse 111 5232 Villigen PSI

  • Zahid Hasan

    • Princeton University

  • Jia-Xin Yin

    • Princeton University
    • Southern University of Science and Technology

  • Titus Neupert

    • Univ of Zurich
    • University of Zurich

  • Johan Chang

    • University of Zurich
    • Universitat Zurich

  • Satoru Nakatsuji

    • Univesity of Tokyo
    • University of Tokyo
    • The University of Tokyo & IQM, Johns Hopkins University
    • The University of Tokyo

  • Ekaterina Pomjakushina

    • Paul Scherrer Institut
    • Paul Scherrer Institute

  • Dariusz Gawryluk

    • Paul Scherrer Institut
    • PSI
    • Paul Scherrer Institute

  • Zurab Guguchia

    • Paul Scherrer Institute
    • soohyeon.shin@psi.ch