Many-body effects in electron spin resonance in 2D systems with Rashba spin-orbit interaction

We report effects of electron–electron (e–e) interaction on electron spin resonance (ESR) in two-dimensional (2D) systems with Rashba spin–orbit interaction (SOI). Using the Hartree–Fock approximation, we demonstrate that Rashba SOI results in non-zero many-body corrections to the ESR energy. We discover that e–e interaction in 2D systems with SOI can not only enhance the ESR energy but also lead to the ESR energy reduction. The magnitude of this effect exhibits remarkable features in a wide range of parameters relevant to experiment: it is found to be rather sensitive to the sign of g-factor and the filling factor of Landau levels ν. We derive analytical expressions for many-body corrections to ESR energy and energy dispersion of spin wave excitations for the case of ν⩽2. We have found out that e–e interaction does not affect the ESR energy in the case of filling of the lowest Landau level (ν⩽1) in 2D systems with positive g-factors even at arbitrarily large values of Rashba constant. The many-body renormalization of ESR energy in the case of fractional Quantum Hall effect is also discussed. (papers)