标题： 极化子流体中的自旋弛豫：量子流体力学方法 显示英文标题

标题： Spin relaxation in a polariton fluid: quantum hydrodynamic approach

摘要： 腔极化子是在强耦合 regime 中出现在量子微腔中的基本激发，表现出量子集体行为的明显特征。 独特自旋结构和强非线性响应的结合为直接实验观察各种非平凡的光学偏振现象提供了可能性。 自旋弛豫过程在此至关重要。 然而，目前尚缺乏对其协同描述的数学形式。 在本文中，基于两组分液体的量子流体动力学方法，我们推导出了一组相应的方程，其中能量和自旋弛豫项自然出现。 我们详细分析了这些项如何影响外部磁场中自旋极化子液滴的动力学以及均匀极化子凝聚体的基本激发的色散。 尽管我们专注于腔极化子的情况，但我们的方法可以应用于其他自旋玻色凝聚体的情况，其中自旋弛豫过程起着重要作用。 显示英文摘要

摘要： Cavity polaritons, the elementary excitations appearing in quantum microcavities in the strong-coupling regime, reveal clear signatures of quantum collective behavior. The combination of unique spin structure and strong nonlinear response opens the possibility of direct experimental observation of a plethora of nontrivial optical polarization phenomena. Spin relaxation processes are of crucial importance here. However, a mathematical formalism for their coherent description is still absent. In the present paper, based on the quantum hydrodynamics approach for a two-component liquid, we derive the set of the corresponding equations where both energy and spin relaxation terms appear naturally. We analyze in detail how these terms affect the dynamics of spinor polariton droplets in the external magnetic field and the dispersion of elementary excitations of a uniform polariton condensate. Although we focus on the case of cavity polaritons, our approach can be applied to other cases of spinor bosonic condensates, where the processes of spin relaxation play a major role.