Lifetime enhanced transport in silicon due to spin and valley blockade

TL;DR

This paper demonstrates Lifetime Enhanced Transport in silicon, revealing how spin and valley blockade lead to extended state lifetimes exceeding 48 ns, which is crucial for silicon quantum device performance.

Contribution

It introduces the observation of LET based on valley physics in silicon and combines experimental transport spectroscopy with theoretical modeling to estimate state lifetimes.

Findings

Lifetime of the state exceeds 48 ns

LET manifests as a current step in the stability diagram

Valley physics significantly influences silicon quantum devices

Abstract

We report the observation of Lifetime Enhanced Transport (LET) based on perpendicular valleys in silicon by transport spectroscopy measurements of a two-electron system in a silicon transistor. The LET is manifested as a peculiar current step in the stability diagram due to a forbidden transition between an excited state and any of the lower energy states due perpendicular valley (and spin) configurations, offering an additional current path. By employing a detailed temperature dependence study in combination with a rate equation model, we estimate the lifetime of this particular state to exceed 48 ns. The two-electron spin-valley configurations of all relevant confined quantum states in our device were obtained by a large-scale atomistic tight-binding simulation. The LET acts as a signature of the complicated valley physics in silicon; a feature that becomes increasingly important in silicon quantum devices.