Two-photon driven magnon-pair resonance as a signature of spin-nematic order
Two-photon driven magnon-pair resonance as a signature of spin-nematic order
复制标题
双光子驱动的磁振子对共振作为自旋向列序的特征
DOI：
10.1103/physrevb.102.060401
复制
发表时间：
2020
影响因子：
3.7
通讯作者：
Morisaku Yoshitaka
中科院分区：
文献类型：
--
作者：
Sato Masahiro;Morisaku Yoshitaka
我们从理论上研究了在不可见的自旋向列有序相附近的完全极化受挫磁体中由强激光或电磁波驱动的非线性磁共振。一般来说，磁振子和磁振子对（双磁振子束缚态）都表现为自旋向列磁体饱和状态下的低能激发。它们的激发能量通常在 10 GHz 到 10 THz 之间。具有角动量的磁振子对可以通过同时吸收两个光子来激发，如果所应用的太赫兹激光足够强，就会发生这种多光子过程。我们计算了具有磁振子 () 和磁振子对 () 类激励的受挫四自旋系统的激光驱动磁动力学，这类似于具有自旋向列相的宏观受挫磁体。我们估计了实现双光子吸收所需的激光磁场强度，并考虑了 Lindblad 方程的耗散效应。我们证明，具有 0.1-1.0 T 交流磁场的强太赫兹激光足以观察磁振子对共振。
We theoretically study the nonlinear magnetic resonance driven by intense lasers or electromagnetic waves in a fully polarized frustrated magnet near a less-visible spin-nematic ordered phase. In general, both magnons and magnon pairs (two-magnon bound state) appear as the low-energy excitation in the saturated state of spin-nematic magnets. Their excitation energies are usually in the range between 10 GHz and 10 THz. Magnon pairs with angular momentumcan be excited by the simultaneous absorption of two photons, and such multiphoton processes occur if the applied THz laser is strong enough. We compute laser-driven magnetic dynamics of a frustrated four-spin system with both magnon () and magnon-pair ()-like excitations, which is analogous to a macroscopic frustrated magnet with a spin-nematic phase. We estimate the required strength of the magnetic field of a laser for the realization of two-photon absorption, taking into account dissipation effects with the Lindblad equation. We show that an intense THz laser with an ac magnetic field of 0.1–1.0 T is enough to observe magnon-pair resonance.