Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Phys Rev Lett. 2019 Oct 18;123(16):167202. doi: 10.1103/PhysRevLett.123.167202.
We propose a new mechanism for the thermal Hall effect in exchange spin-wave systems, which is induced by the magnon-phonon interaction. Using symmetry arguments, we first show that this effect is quite general, and exists whenever the mirror symmetry in the direction of the magnetization is broken. We then demonstrate our result in a collinear ferromagnet on a square lattice, with perpendicular easy-axis anisotropy and Dzyaloshinskii-Moriya interaction from mirror symmetry breaking. We show that the thermal Hall conductivity is controlled by the resonant contribution from the anticrossing points between the magnon and phonon branches, and estimate its size to be comparable to that of the magnon-mediated thermal Hall effect.
我们提出了一种交换自旋波系统中热霍尔效应的新机制，该机制由磁振子-声子相互作用引起。通过对称论证，我们首先表明，只要沿磁化方向的镜像对称被破坏，这种效应就相当普遍。然后，我们在具有垂直易轴各向异性和由镜像对称破坏引起的 Dzyaloshinskii-Moriya 相互作用的正方形晶格上的共线铁磁体中演示了我们的结果。我们表明，热霍尔电导率由磁振子和声子支之间的交叉点的共振贡献控制，并估计其大小可与磁子介导的热霍尔效应相媲美。
