Negative Differential Spin Conductance by Population Switching

TL;DR

This paper predicts a novel phenomenon called negative differential spin conductance (NDSC), where increasing bias voltage decreases spin-specific current, using a many-body master equation approach in Coulomb blockade systems.

Contribution

It introduces the concept of negative differential conductance per spin (NDSC) and demonstrates its potential occurrence with a detailed theoretical model.

Findings

Identification of negative differential conductance per spin (NDSC)

Demonstration of NDSC using a many-body master equation model

Analysis within Coulomb blockade regime

Abstract

An examination of the properties of many-electron conduction through spin-degenerate systems can lead to situations where increasing the bias voltage applied to the system is predicted to decrease the current flowing through it, for the electrons of a particular spin. While this does not necessarily constitute negative differential conductance (NDC) per se, it is an example of negative differential conductance per spin (NDSC) which to our knowledge is discussed here for the first time. Within a many-body master equation approach which accounts for charging effects in the Coulomb Blockade regime, we show how this might occur.