Enhancement of the Kondo Effect through Rashba Spin-Orbit Interactions

We study a one-orbital Anderson impurity in a two-dimensional electron bath with Rashba spin-orbit interactions in the Kondo regime. The spin SU(2) symmetry-breaking term couples the impurity to a two-band electron gas. A Schrieffer-Wolff transformation shows the existence of the Dzyaloshinsky-Moriya interaction away from the particle-hole symmetric impurity state. A renormalization group analysis reveals a two-channel Kondo model with ferro- and antiferromagnetic couplings. The parity-breaking Dzyaloshinsky-Moriya term renormalizes the antiferromagnetic Kondo coupling with an exponential enhancement of the Kondo temperature.

Figure 1

The Kondo temperature enhancement due to RSO grows exponentially with ${\lambda }_F$. The inset shows the schematics of the magnetic adatom on the 2d electron gas system with the RSO coupling, where the states for a given momentum have a definite spin.