Suppression of low-frequency noise in two-dimensional electron gas at degenerately doped Si:P \delta-layers

TL;DR

This study demonstrates extremely low 1/f noise in degenerately doped Si:P delta-layers at 4.2K, significantly lower than bulk Si:P, with implications for low-noise electronic applications.

Contribution

It reports the first measurement of ultra-low 1/f noise in 2D Si:P delta-layers, highlighting their potential for low-noise electronic devices.

Findings

Noise is over six orders of magnitude lower than bulk Si:P.

Noise is nearly independent of magnetic field at low fields.

Electron interaction with structural two-level systems may explain the noise level.

Abstract

We report low-frequency 1/f noise measurements of degenerately doped Si:P \delta-layers at 4.2K. The noise was found to be over six orders of magnitude lower than that of bulk Si:P systems in the metallic regime and is one of the lowest values reported for doped semiconductors. The noise was found to be nearly independent of magnetic field at low fields, indicating negligible contribution from universal conductance fluctuations. Instead interaction of electrons with very few active structural two-level systems may explain the observed noise magnitude