Long-term drift of Si-MOS quantum dots with intentional donor implants

TL;DR

This study investigates charge noise and drift in Si-MOS quantum dots with implanted donors, finding that implantation does not worsen long-term stability or noise levels, which are comparable to non-implanted systems.

Contribution

It demonstrates that intentional donor implantation in Si-MOS quantum dots does not adversely affect long-term charge stability or noise, supporting scalable qubit fabrication.

Findings

Charge offset drift shows non-equilibrium transients and jumps.

Charge noise follows a 1/f dependence with low noise levels.

Implanted qubits maintain stable long-term charge characteristics.

Abstract

Charge noise can be detrimental to the operation of quantum dot (QD) based semiconductor qubits. We study the low-frequency charge noise by charge offset drift measurements for Si-MOS devices with intentionally implanted donors near the QDs. We show that the MOS system exhibits non-equilibrium drift characteristics in the form of transients and discrete jumps that are not dependent on the properties of the donor implants. The equilibrium charge noise indicates a $1/f$ noise dependence, and a noise strength as low as $1~\mathrm{\mu eV/\sqrt{Hz}}$, comparable to that reported in more model GaAs and Si/SiGe systems (which have also not been implanted). We demonstrate that implanted qubits, therefore, can be fabricated without detrimental effects on long-term drift or $1/f$ noise.