Ring Exchange Effects on Magnons in Topological Dirac Magnet CoTiO<sub>3</sub>

ORAL

Abstract

The study of the interplay between topology and magnetism has begun to show a plethora of candidate materials where magnons can be classified as topological (arxiv:2206.06248). One recent example of a potential topological magnetic material is CoTiO3. We use a combination of time domain THz (TDTS) and magneto-Raman spectroscopies to measure the low energy magnetic spectrum in CoTiO3 and detect the two lowest energy magnons, one of which is the gapped Goldstone mode which responds to THz magnetic field perpendicular to the honeycomb plane, and the other is an inversion even optical magnon which is active for THz magnetic field parallel to the honeycomb plane. We build a theoretical model that can explain the opening of the gap of the pseudo Goldstone magnon and the magnetic field dependence of the two magnons with the apperance of a small ring exchange interaction between 6 spins in a hexagonal plaquette. This study shows the power of combining TDTS and Raman spectroscopies with theoretical modeling to understand the nature of the magnetic excitations in quantum magnets.

*Work at OSU and CSU was supported by the Center for Emergent Materials at OSU, a Materials Research Science and Engineering Center funded by NSF under grant DMR-2011876.

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Presenters

  • Rolando Valdes Aguilar

    • Ohio State University

Authors

  • Rolando Valdes Aguilar

    • Ohio State University

  • Yufei Li

    • Ohio State University

  • Thuc T Mai

    • National Institute of Standards and Technology

  • Evan Jasper

    • Ohio State Univ - Columbus

  • Mohammed Karaki

    • Ohio State University

  • Kevin F Garrity

    • National Institute of Standards and Tech

  • Chase L Lyon

    • Ohio State University

  • Daniel Shaw

    • Colorado State University

  • Timothy N DeLazzer

    • Colorado State University

  • Adam Biacchi

    • National Institute of Standards and Technology (NIST)
    • National Institute of Standards and Technology

  • Rebecca L Dally

    • National Institute of Standards and Technology
    • National Institute of Standards and Tech

  • Daniel M Heligman

    • Ohio State Univ - Columbus

  • Jared Gdanski

    • The Ohio State University

  • Tehseen Adel

    • National Institute of Standards and Technology

  • Alex D Giovannone

    • The Ohio State University

  • Maria F Munoz

    • National Institute of Standards and Technologies

  • Jeffrey R Simpson

    • Towson University

  • Kate A Ross

    • Colorado State University

  • Nandini Trivedi

    • The Ohio State University
    • Ohio State University

  • Yuan-Ming Lu

    • Ohio State Univ - Columbus

  • Angela R Hight Walker

    • National Institute of Standards and Tech
    • National Institute of Standards and Technology