Charge State Hysteresis in Semiconductor Quantum Dots

TL;DR

This paper studies charge hysteresis in silicon quantum dots, revealing hysteretic tunneling behavior that depends on charge history, and models this phenomenon to show potential for single-electron memory applications.

Contribution

It introduces a model explaining charge hysteresis in quantum dots and demonstrates their operation as single-electron memory latches.

Findings

Hysteretic tunneling events depend on charge history

Model extends existing transport descriptions for double dots

Device functions as a single-electron memory latch

Abstract

Semiconductor quantum dots provide a two-dimensional analogy for real atoms and show promise for the implementation of scalable quantum computers. Here, we investigate the charge configurations in a silicon metal-oxide-semiconductor double quantum dot tunnel coupled to a single reservoir of electrons. By operating the system in the few-electron regime, the stability diagram shows hysteretic tunnelling events that depend on the history of the dots charge occupancy. We present a model which accounts for the observed hysteretic behaviour by extending the established description for transport in double dots coupled to two reservoirs. We demonstrate that this type of device operates like a single-electron memory latch.