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Electron-phonon effects on spin-orbit split bands of two dimensional systems

E. Cappelluti·C. Grimaldi·F. Marsiglio
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Abstract

The electronic self-energy is studied for a two dimensional electron gas coupled to a spin-orbit Rashba field and interacting with dispersionless phonons. For the case of a momentum independent electron-phonon coupling (Holstein model) we solve numerically the self-consistent non-crossing approximation for the self-energy and calculate the electron mass enhancement $m^*/m$ and the spectral properties. We find that, even for nominal weak electron-phonon interaction, for strong spin-orbit couplings the electrons behave as effectively strongly coupled to the phonons. We interpret this result by a topological change of the Fermi surface occurring at sufficiently strong spin-orbit coupling, which induces a square-root divergence in the electronic density of states at low energies. We provide results for $m^*/m$ and for the density of states of the interacting electrons for several values of the electron filling and of the spin-orbit interaction.

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E. Cappelluti, C. Grimaldi, F. Marsiglio. 2007-08-28. Electron-phonon effects on spin-orbit split bands of two dimensional systems. https://doi.org/10.1103/physrevb.76.085334

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