Protection of a non-Fermi liquid by spin-orbit interaction

TL;DR

This paper demonstrates that strong spin-orbit interaction can protect non-Fermi liquid behavior in a quantum dot system from magnetic field destruction, with thermoelectric properties highly dependent on magnetic field orientation.

Contribution

It introduces a mechanism where spin-orbit interaction preserves non-Fermi liquid behavior against magnetic fields in quantum dot devices, highlighting the role of spin scattering processes.

Findings

Spin-orbit interaction protects NFL behavior from magnetic field effects.

Thermoelectric coefficients depend strongly on magnetic field orientation.

A parameter window exists for experimental observation of NFL effects.

Abstract

We show that a thermoelectric transport through a Quantum Dot (QD) - single-mode Quantum Point Contact (QPC) nano-device demonstrating pronounced fingerprints of Non-Fermi Liquid (NFL) behavior in the absence of external magnetic field is protected from magnetic field NFL destruction by strong spin-orbit interaction (SOI). The mechanism of protection is associated with appearance of additional scattering processes due to lack of spin conservation in the presence of both SOI and small Zeemann field. The interplay between in-plane magnetic field $\vec B$ and SOI is controlled by the angle between $\vec B$ and $\vec B_{SOI}$ We predict strong dependence of the thermoelectric coefficients on the orientation of the magnetic field and discuss a window of parameters for experimental observation of NFL effects.