Zero-Field Satellites of a Zero-Bias Anomaly

Spin-orbit (SO) splitting, $\pm {\omega }_{SO}$, of the electron Fermi surface in two-dimensional systems manifests itself in the interaction-induced corrections to the tunneling density of states, $\nu (ϵ)$. Namely, in the case of a smooth disorder, it gives rise to the satellites of a zero-bias anomaly at energies $ϵ=\pm 2{\omega }_{SO}$. Zeeman splitting, $\pm \omega_{Z}$, in a weak parallel magnetic field causes a narrow {\em plateau} of a width $\delta ϵ=2{\omega }_Z$ at the top of each sharp satellite peak. As ${\omega }_Z$ exceeds ${\omega }_{SO}$, the SO satellites cross over to the conventional narrow maxima at $ϵ=\pm 2{\omega }_Z$ with SO-induced plateaus $\delta ϵ=2{\omega }_{SO}$ at the tops.