Pauli spin blockade in cotunneling transport through a double quantum dot

TL;DR

This paper investigates Pauli spin blockade effects in cotunneling transport through a double quantum dot with few electrons, revealing current rectification and negative differential conductance explained by spin blockade mechanisms.

Contribution

It provides a detailed analysis of spin blockade phenomena in double quantum dots, incorporating models with both coherent and incoherent interdot coupling.

Findings

Observation of current rectification with negative differential conductance

Explanation of transport features via Pauli spin blockade

Connection of current features to exchange singlet-triplet splitting

Abstract

We study spin correlation in a double quantum dot containing a few electrons in each dot (around 10). Clear current rectification with negative differential conductance is observed in the cotunneling regime, which is well explained by a Pauli spin blockade. The current feature is discussed in connection with exchange singlet-triplet splitting based on two simple models, one of which takes coherent interdot coupling and the other incoherent interdot coupling into account.