Programmable quantum emitter formation in silicon

TL;DR

This paper demonstrates a method to locally create and erase silicon-based quantum emitters using femtosecond laser pulses, hydrogen defect passivation, and thermal annealing, enabling programmable quantum emitter formation for scalable quantum technologies.

Contribution

It introduces a novel approach combining laser pulses and hydrogen passivation to selectively form and erase quantum emitters in silicon, advancing scalable quantum device fabrication.

Findings

Formation of telecom S-band Ci centers with promising spin properties.

Hydrogen enhances the brightness of Ci centers by orders of magnitude.

Laser pulses enable programmable, localized control of quantum emitter creation.

Abstract

Silicon-based quantum emitters are candidates for large-scale qubit integration due to their single-photon emission properties and potential for spin-photon interfaces with long spin coherence times. Here, we demonstrate local writing and erasing of selected light-emitting defects using fs laser pulses in combination with hydrogen-based defect activation and passivation. By selecting forming gas (N2/H2) during thermal annealing of carbon-implanted silicon, we form Ci centers while passivating the more common G-centers. The Ci center is a telecom S-band emitter with very promising spin properties that consists of a single interstitial carbon atom in the silicon lattice. Density functional theory calculations show that the Ci center brightness is enhanced by several orders of magnitude in the presence of hydrogen. Fs-laser pulses locally affect the passivation or activation of quantum emitters with hydrogen and enable programmable quantum emitter formation in a qubit-by-design paradigm.