论文标题
带有Rashba旋转轨道相互作用的二维Schwinger-boson气体的热厅效应：应用于平面内dzyaloshinskii-Moriya相互作用的铁磁体
Thermal Hall effect from two-dimensional Schwinger-boson gas with Rashba spin-orbit interaction: application to ferromagnets with in-plane Dzyaloshinskii-Moriya interaction
论文作者
论文摘要
最近，发现绝缘子中热厅效应的来源已成为一个重要的问题。在铁磁绝缘子的情况下，众所周知，dzyaloshinskii-moriya（DM）相互作用可以诱导镁热室效应。具体而言，与磁化方向平行的DM矢量会诱导复杂的镁跳振幅，从而使镁像感觉到洛伦兹的力一样。但是，与磁化方向正交的DM矢量迄今已被忽略为镁热霍尔效应的可能来源。这是因为它们在线性旋转波理论中没有任何作用，这是计算磁蛋白热厅效应时通常被调用的近似值。在这里，我们通过介绍具有铁磁Heisenberg相互作用和平面内DM相互作用的二维磁体的自洽的Schwinger-Boson平均现场研究来挑战这一期望。我们发现，相关的Schwinger-Boson平均场汉密尔顿（Hamiltonian）采用了带有Rashba自旋轨道相互作用的二维电子气体的形式，众所周知，它显示出异常的霍尔效应，自旋霍尔效应和Rashba-Edelstein效应，其热对应物也出现在我们的系统中。重要的是，当应用平面磁场时，可以诱导热厅效应，即使磁场很大，也可以持续存在，因此旋转显着极化，并且预期线性自旋波理论是合理的近似值。由于线性旋转波理论预测了消失的热霍尔效应，因此我们的结果意味着线性自旋波不足以近似，并且必须考虑磁杆磁通的相互作用以预测正确的热霍尔电导率。
Recently, uncovering the sources of thermal Hall effect in insulators has become an important issue. In the case of ferromagnetic insulators, it is well known that Dzyaloshinskii-Moriya (DM) interaction can induce magnon thermal Hall effect. Specifically, the DM vector parallel to the magnetization direction induces complex magnon hopping amplitudes, so that magnons act as if they feel Lorentz force. However, the DM vector which is orthogonal to the magnetization direction has hitherto been neglected as a possible source of magnon thermal Hall effect. This is because they play no role in the linear spin wave theory, an often invoked approximation when computing the magnon thermal Hall effect. Here, we challenge this expectation by presenting the self-consistent Schwinger-boson mean field study of two-dimensional magnets with ferromagnetic Heisenberg interaction and in-plane DM interaction. We find that the relevant Schwinger-boson mean field Hamiltonian takes the form of two-dimensional electron gas with Rashba spin-orbit interaction, which is known to show anomalous Hall effect, spin Hall effect, and Rashba-Edelstein effect, whose thermal counterparts also appear in our system. Importantly, the thermal Hall effect can be induced when out-of-plane magnetic field is applied, and persists even when the magnetic field is large, so that the spins are significantly polarized, and the linear spin wave theory is expected to be a reasonable approximation. Since the linear spin wave theory predicts vanishing thermal Hall effect, our result implies that linear spin wave is not a sufficient approximation, and that magnon-magnon interaction must be taken into account to predict the correct thermal Hall conductivity.
