Spin effects in transport through non-Fermi liquid quantum dots

TL;DR

This paper investigates how spin effects and non-Fermi liquid correlations influence transport properties in one-dimensional quantum dots, revealing spin-induced parity effects, temperature-dependent conductance peak shifts, and negative differential conductances under certain conditions.

Contribution

It demonstrates the impact of spin and non-Fermi liquid correlations on quantum dot conductance, including spin-induced parity effects and conditions for negative differential conductance.

Findings

Spin-induced parity effect in conductance peaks at zero temperature.

Negative differential conductance predicted for non-symmetric barriers.

Spin relaxation destroys the observed conductance features.

Abstract

The current-voltage characteristic of a one dimensional quantum dot connected via tunnel barriers to interacting leads is calculated in the region of sequential tunneling. The spin of the electrons is taken into account. Non-Fermi liquid correlations implying spin-charge separation are assumed to be present in the dot and in the leads. It is found that the energetic distance of the peaks in the linear conductance shows a spin-induced parity effect at zero temperature T. The temperature dependence of the positions of the peaks depends on the non-Fermi liquid nature of the system. For non-symmetric tunnel barriers negative differential conductances are predicted, which are related to the participation in the transport of collective states in the quantum dot with larger spins. Without spin-charge separation the negative differential conductances do not occur. Taking into account spin relaxation destroys the spin-induced conductance features. The possibility of observing in experiment the predicted effects are briefly discussed.