Quantum Transport in 40-nm MOSFETs at Deep-Cryogenic Temperatures

TL;DR

This study investigates 40-nm MOSFETs at deep cryogenic temperatures, revealing their potential for quantum information processing by exhibiting classical and quantum behaviors, including Coulomb blockade, with promising uniformity for scalable quantum computing integration.

Contribution

It provides the first detailed characterization of commercial 40-nm MOSFETs at deep cryogenic temperatures, demonstrating their suitability for quantum and classical co-integration in quantum computing.

Findings

Devices operate as classical FETs or quantum dots at 50 mK.

All devices show Coulomb blockade in the quantum regime.

Variability approaches requirements for shared control in quantum scaling.

Abstract

In this letter, we characterize the electrical properties of commercial bulk 40-nm MOSFETs at room and deep cryogenic temperatures, with a focus on quantum information processing (QIP) applications. At 50 mK, the devices operate as classical FETs or quantum dot devices when either a high or low drain bias is applied, respectively. The operation in classical regime shows improved transconductance and subthreshold slope with respect to 300 K. In the quantum regime, all measured devices show Coulomb blockade. This is explained by the formation of quantum dots in the channel, for which a model is proposed. The variability in parameters, important for quantum computing scaling, is also quantified. Our results show that bulk 40-nm node MOSFETs can be readily used for the co-integration of cryo-CMOS classical-quantum circuits at deep cryogenic temperatures and that the variability approaches the uniformity requirements to enable shared control.