Spin blockade and lifetime-enhanced transport in a few-electron Si/SiGe double quantum dot

TL;DR

This paper reports on spin blockade and lifetime-enhanced transport in a silicon double quantum dot, highlighting long spin lifetimes that enable improved control for quantum computing and spintronics applications.

Contribution

It demonstrates the observation of spin blockade and lifetime-enhanced transport in silicon quantum dots, emphasizing the role of long spin decay times in these phenomena.

Findings

Observation of spin blockade in silicon double quantum dots

Identification of lifetime-enhanced transport due to long spin decay times

Implications for quantum computation and spintronics

Abstract

Spin blockade occurs when an electron is unable to access an energetically favorable path through a quantum dot due to spin conservation, resulting in a blockade of the current through the dot. Spin blockade is the basis of a number of recent advances in spintronics, including the measurement and the manipulation of individual electron spins. We report measurements of the spin blockade regime in a silicon double quantum dot, revealing a complementary phenomenon: lifetime-enhanced transport. We argue that our observations arise because the decay times for electron spins in silicon are long, enabling the electron to maintain its spin throughout its transit across the quantum dot and access fast paths that exist in some spin channels but not in others. Such long spin lifetimes are important for applications such as quantum computation and, more generally, spintronics.