Investigation of Real-Space Transfer Noise in InP Quantum Wells

TL;DR

This study experimentally investigates the role of real-space transfer in drain noise of InP HEMTs, providing evidence that RST significantly contributes to microwave noise performance.

Contribution

It experimentally tests and supports a theoretical model linking real-space transfer to drain noise in InP quantum well transistors.

Findings

Noise temperature varies with physical temperature and source-drain voltage.

Results align with RST noise theory predictions.

Supports RST as a key noise mechanism in InP HEMTs.

Abstract

Indium phosphide (InP) high electron-mobility transistors (HEMTs) are widely used in many fields such as quantum computing because of their unparalleled microwave noise performance. Achieving improved noise performance requires a physical understanding of the noise mechanisms. Here, we experimentally test a theoretical proposal for drain (output) noise as originating in part from real-space transfer (RST) by characterizing the microwave noise temperature of transfer-length method structures with the same channel composition but two different barrier compositions. This choice was made to alter the confining potential of electrons in the channel, thereby affecting the RST mechanism, while avoiding changes to the channel transport properties. We observe trends of noise temperature with physical temperature and source-drain voltage which are compatible with the predictions of RST noise theory. This finding supports the hypothesis that RST contributes to drain noise in HEMTs.