Kondo effect under the influence of spin-orbit coupling in a quantum wire

Area of Science:

• Condensed Matter Physics
• Quantum Mechanics
• Materials Science

Background:

• The impact of spin-orbit coupling (SOC) on the Kondo state, particularly its effect on Kondo temperature (T_K), remains a subject of debate.
• Understanding these interactions is crucial for designing novel electronic devices and spintronic applications.

Purpose of the Study:

• To investigate the influence of Rashba and Dresselhaus SOC on the Kondo temperature in a one-dimensional single impurity Anderson model (SIAM).
• To provide an analytical framework for understanding SOC's role in Kondo physics and resolve existing controversies.

Main Methods:

• Utilized the one-dimensional single impurity Anderson model (SIAM) with both Rashba and Dresselhaus SOC.
• Employed analytical techniques, including a physically motivated change of basis and the Haldane expression, to derive renormalized parameters.
• Validated analytical findings using numerical renormalization group (NRG) and the projector operator approach.

Main Results:

• Demonstrated that SOC in the quantum wire exponentially decreases T_K, while SOC at the impurity exponentially increases it.
• Showed that the finite-SOC SIAM retains a Kondo ground state due to time-reversal symmetry, similar to the zero-SOC case.
• Observed a persistent spin helix SU(2) symmetry in the 1D SOC SIAM for arbitrary SOC strengths.

Conclusions:

• The study provides a clear analytical and numerical understanding of SOC's opposing effects on T_K depending on its location.
• The findings resolve controversies regarding SOC's dependence on T_K and offer a method for predicting its behavior.
• The identified persistent spin helix symmetry opens avenues for exploring novel quantum phenomena and device functionalities.