Effect of randomness on spin excitations in quantum spin liquid state of 1T-TaS2

ORAL

Abstract

Quantum spin liquid (QSL) is a novel state of matter where the ground states are quantum mechanically entangled and have several characteristic features, including fractional excitations. However, the nature of QSLs remains elusive. To tackle this problem, studying the effect of quenched disorder is of vital importance.
Recently, 1T-TaS2 has aroused great interest as a candidate material that hosts a QSL ground state on two-dimensional perfect triangular lattice as suggested both theoretically and experimentally[1, 2]. To study the effect of randomness on the QSL state, we performed thermal conductivity and specific heat measurements on pure, Se-doped and electron irradiated 1T-TaS2. The results indicate the coexistence of itinerant and localized gapless spin excitations, suggesting a novel spin liquid state where itinerant quasiparticles coexist with randomly distributed orphan spins forming localized random singlets. In addition, thermal conductivity reveals the suppression of gapless spin excitations by Se-doping, indicating that the itinerant gapless spin excitations are sensitive to randomness. We will also discuss the effect of randomness on the specific heat.
[1] K. T. Law and P. A. Lee, PNAS 114, 6996 (2017).
[2] M. Klanjsek, et al., Nat. Phys. 13, 1130 (2017).

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Presenters

  • Hinako Murayama

    Physics, Kyoto University, Department of Physics, Kyoto University, Kyoto University

Authors

  • Hinako Murayama

    Physics, Kyoto University, Department of Physics, Kyoto University, Kyoto University

  • Yuki Sato

    Physics, Kyoto University, Department of Physics, Kyoto University, Kyoto University

  • Tomoya Taniguchi

    Physics, Kyoto University, Department of Physics, Kyoto University

  • Ryo Kurihara

    Department of Physics, Kyoto University, Kyoto University

  • xiangzhuo xing

    Department of Physics, Kyoto University

  • Shigeru Kasahara

    Physics, Kyoto University, Dept of Physics, Kyoto Univ., Kyoto University, Department of Physics, Kyoto University

  • Yuichi Kasahara

    Department of Physics, Kyoto University, Physics, Kyoto University, Kyoto University

  • Masaro Yoshida

    RIKEN Center for Emergent Matter Science, CEMS, RIKEN

  • Yoshihiro Iwasa

    Department of Applied Physics, The University of Tokyo, University of Tokyo, Department of applied physics, University of Tokyo, Department of Applied Physics, University of Tokyo, Quantum-Phase Electronics Center and Department of Applied Physics, University of Tokyo

  • Marcin Konczykowski

    Laboratoire des Solides Irradiés, École Polytechnique, F-91128 Palaiseau, France, Ecole Polytechnique, Ecole Polytechnique, Palaiseau, France, LSI, Ecole Polytechnique, Laboratoire des Solides Irradies, Ecole Polytechnique

  • Yuji Matsuda

    Physics, Kyoto University, Department of Physics, Kyoto University, Dept of Physics, Kyoto Univ., Kyoto University