论文标题
磁场和相对论巴内特效应引起的自旋极化
Spin polarization induced by magnetic field and the relativistic Barnett effect
论文作者
论文摘要
首先，我研究材料的磁化和流体中颗粒的自旋极化之间的类比。使用Barnett效应的相对论版本，即通过机械旋转引起的材料的磁化，在纯粹的经典模型中获得了由热涡度诱导的自旋极化，其中旋转被视为内在的磁矩和旋转作为非惯性效应。我认为，由于可以在经典理论中获得热涡度引起的自旋极化，因此不能由量子异常主导。 其次，使用统计量子场理论，在局部热平衡处获得了磁场引起的自旋极化。所获得的公式在弱场近似之外以及磁场非同质性的贡献时有效。研究了自旋极化的确切形式，以在整体平衡处进行自由狄拉克场，并且像磁敏感性一样，它会根据de haas -van alphen效应振荡。 最后，我简要回顾了磁场如何促进$λ$的自旋极化与在重型离子碰撞中观察到的$ \barλ$之间的差异。
First, I study the analogy between the magnetization of a material and the spin polarization of particles in a fluid. Using the relativistic version of the Barnett effect, i.e. the magnetization of a material induced by mechanical rotation, the spin polarization induced by thermal vorticity is obtained within a purely classical model, where spin is treated as an intrinsic magnetic moment and rotation is included as a non-inertial effect. I argue that since spin polarization induced by thermal vorticity can be obtained in a classical theory, it can not be dominated by quantum anomalies. Second, the spin polarization induced by magnetic field is obtained for a fluid at local thermal equilibrium using statistical quantum field theory. The obtained formula is valid beyond the weak field approximation and when contributions from the non-homogeneity of the magnetic field are small. The exact form of spin polarization is studied for a free Dirac field at global equilibrium, and, like magnetic susceptibility, it oscillates according to the de Haas - van Alphen effect. Finally, I briefly review how magnetic field contributes to the difference between the spin polarization of $Λ$ and $\barΛ$ observed in heavy-ion collisions.
