Negative differential conductance induced by spin-charge separation

TL;DR

This paper investigates how spin-charge separation in a one-dimensional quantum dot with interacting leads can cause negative differential conductance due to correlation effects, notably trapping higher-spin states and increasing spin fluctuations.

Contribution

It reveals the mechanism of negative differential conductance caused by spin-charge separation in non-linear transport through quantum dots with asymmetric barriers.

Findings

Negative differential conductance regions are observed.

Spin-charge separation leads to trapping of higher-spin states.

Spin fluctuations significantly increase during these regions.

Abstract

Spin-charge states of correlated electrons in a one-dimensional quantum dot attached to interacting leads are studied in the non-linear transport regime. With non-symmetric tunnel barriers, regions of negative differential conductance induced by spin-charge separation are found. They are due to a correlation-induced trapping of higher-spin states without magnetic field, and associated with a strong increase in the fluctuations of the electron spin.