High Temperature Magnon Thermal Conductivity in Cuprates

ORAL

Abstract

Some cuprates have high thermal conductivities due to the strong exchange interaction, which leads to high magnon group velocities. However, little is known about the behavior of the magnons in the cuprates above room temperature. In our study, we use the time-domain thermoreflectance (TDTR) to investigate the high magnon thermal conductivities of different cuprates at temperatures from 75 K to 600 K. Each of the cuprates studied has a different arrangement of spin-spin coupling: SrCuO2 (a spin-chain), CaCu2O3 (a buckled spin ladder/pseudo-two-leg-ladder), and La2CuO4 (a two-dimensional square lattice). CaCu2O3 and La2CuO4 have peaks in their thermal conductivities near room temperature (~300K), but the temperature dependence of thermal conductivity differs at higher temperatures. While SrCuO2 has a monotonically decreasing thermal conductivity with temperature, its thermal conductivity at higher temperatures are still at least two times higher than the other two cuprates. Our work seeks to explain how different arrangements of spin-spin coupling, the spin-phonon interaction, and magnetic dispersion lead to the different behaviors of thermal conductivity in these cuprates.

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Presenters

  • ELLA PEK

    Univ of Illinois - Urbana

Authors

  • ELLA PEK

    Univ of Illinois - Urbana

  • Xi Chen

    University of Texas, at Austin

  • Sean Sullivan

    University of Texas, at Austin

  • Jianshi Zhou

    Univ of Texas, University of Texas, University of Texas at Austin, Texas Materials Institute, University of Texas at Austin, Univ of Texas, Austin, Mechanical Engineering, University of Texas at Austin, University of Texas, at Austin

  • Li Shi

    University of Texas at Austin, University of Texas, at Austin

  • David Cahill

    Materials Science and Engineering, University of Illinois at Urbana-Champaign, Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, University of Illinois at Urbana-Campaign, University of Illinois at Urbana-Champaign, University of Illinois at Urbana–Champaign, Department of Materials Science and Engineering and Materials Research Laboratory, Univ of Illinois - Urbana, Univ of Illinois - Urbana, Univ of Illinois at Urbana-Champaign, Department of Materials Science and Engineering, University of Illinois