Chiral spin resonance and spin-Hall conductivity in the presence of the   electron-electron interactions
  We discuss the electron spin resonance in two-dimensional electron gas at zero external magnetic field. This spin-resonance is due to the transitions between the electron states, which are split by the spin-orbit (SO) interaction, and is termed as the chiral spin resonance (CSR). It can be excited by the in-plane component of the electric field of microwave radiation. We show that there exists an inherent relationship between the spin-Hall conductivity and the CSR in a system with the SO interaction. Since in the presence of the SO interaction spin is not conserved, the electron-electron interaction renormalizes the spin-Hall conductivity as well as the frequency of the CSR. The effects of the electron interaction in systems with the SO interaction are analyzed both phenomenologically and microscopically. 
A. Shekhter, M. Khodas and A.M. Finkel'stein