Department of Physics, University of Florida, Gainesville, Florida 32611, USA.
National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA.
Phys Rev Lett. 2015 Apr 17;114(15):156803. doi: 10.1103/PhysRevLett.114.156803.
A Fermi liquid with spin-orbit coupling (SOC) is expected to support a new set of collective modes: oscillations of magnetization in the absence of the magnetic field. We show that these modes are damped by the electron-electron interaction even in the limit of an infinitely long wavelength (q=0). The linewidth of the collective mode is on the order of Δ¯2/E(F), where Δ¯ is a characteristic spin-orbit energy splitting and E(F) is the Fermi energy. Such damping is in stark contrast to known damping mechanisms of both charge and spin collective modes in the absence of SOC, all of which disappear at q=0, and arises because none of the components of total spin is conserved in the presence of SOC.
具有自旋轨道耦合（SOC）的费米液体预计将支持一组新的集体模式：在没有磁场的情况下磁化强度的振荡。我们表明，即使在无穷长波长（q=0）的极限下，这些模式也会被电子-电子相互作用阻尼。集体模式的线宽约为Δ¯2/E(F)，其中Δ¯是特征自旋轨道能量分裂，E(F)是费米能。这种阻尼与 SOC 存在时电荷和自旋集体模式的已知阻尼机制形成鲜明对比，SOC 存在时所有这些机制在 q=0 时都消失了，这是因为在 SOC 存在的情况下总自旋的任何分量都不守恒。
