论文标题
通过自旋纽绝缘系统引起的自旋 - 纽马波动引起的磁敏感性的强大增强，并具有自旋轨道耦合
Strong enhancement of magnetic susceptibility induced by spin-nematic fluctuations in an excitonic insulating system with spin-orbit coupling
论文作者
论文摘要
研究了自旋轨道耦合（SOC）和磁场对激发隔膜（EI）状态的影响。我们介绍了具有晶体场拆分的两轨哈伯德模型，这是一个最小的模型，用于讨论强相关的电子系统中的激子凝结，并使用平均场理论分析其在强相关极限中的有效汉密尔顿人。在没有SOC和磁场的情况下，基态通过增加hund耦合而从非磁性带构造状态变为EI状态。在应用的磁场中，磁矩出现在EI状态下，该状态连续连接到强制铁磁状态。另一方面，在SOC的存在下，它们被相边界隔开。我们发现，在边界附近的EI阶段，磁敏感性通过小型SOC在边界附近得到了强烈的增强。这种特殊的行为归因于高旋转局部固定在hund耦合稳定的高旋转状态固有的自旋列性的低能波动。本研究不仅揭示了SOC对EI状态的影响，而且还阐明了EI状态自旋源性的量子波动的作用。
Effects of the spin-orbit coupling (SOC) and magnetic field on excitonic insulating (EI) states are investigated. We introduce the two-orbital Hubbard model with the crystalline field splitting, which is a minimal model for discussing the exciton condensation in strongly correlated electron systems, and analyze its effective Hamiltonian in the strong correlation limit by using the mean-field theory. In the absence of the SOC and magnetic field, the ground state changes from the nonmagnetic band-insulating state to the EI state by increasing the Hund coupling. In an applied magnetic field, the magnetic moment appears in the EI state, which is continuously connected to the forced ferromagnetic state. On the other hand, in the presence of the SOC, they are separated by a phase boundary. We find that the magnetic susceptibility is strongly enhanced in the EI phase near the boundary with a small SOC. This peculiar behavior is attributed to the low-energy fluctuation of the spin nematicity inherent in the high-spin local state stabilized by the Hund coupling. The present study not only reveals the impact of the SOC for the EI state but also sheds light on the role of quantum fluctuations of the spin nematicity for the EI state.
