Spin polarized current and shot noise in carbon nanotube quantum dot in the Kondo regime

TL;DR

This paper investigates spin-dependent transport and shot noise in a carbon nanotube quantum dot within the Kondo regime, highlighting potential for high tunnel magnetoresistance and gate control, with analysis of symmetry breaking effects.

Contribution

It introduces a detailed theoretical analysis of spin-dependent conductance and shot noise in the Kondo regime of carbon nanotube quantum dots, including effects of symmetry breaking and external perturbations.

Findings

Giant tunnel magnetoresistance can be achieved in this regime.

Gate control of magnetoresistance is feasible.

Spin-flip processes significantly influence shot noise.

Abstract

Using nonequilibrium Green functions and several complementary many-body approximations we calculate shot noise and spin dependent conductance in carbon nanotube semiconducting quantum dot in spin-orbital Kondo regime. We point out on the possibility of reaching giant values of tunnel magnetoresistance in this range and discuss a prospect of its gate control. We also analyze the influence of symmetry breaking perturbations on the shot noise with special emphasis on spin dependent effects. The gate and bias dependencies of noise Fano factors influenced by magnetic field, polarization of electrodes and spin-flip processes are presented.