Incorporation and control of defects with quantum functionality during sublimation growth of cubic silicon carbide

TL;DR

This paper explores a novel method to incorporate and control deep level defects, specifically carbon vacancies, in cubic silicon carbide during sublimation growth, aiming to enable quantum functionalities at higher temperatures.

Contribution

It introduces a new growth-based approach to intentionally incorporate and control defects in SiC for quantum applications, moving beyond accidental defect formation.

Findings

Defects show bright luminescence at 175-200 K and are excitable up to 300 K.

All detected defects are attributed to carbon vacancies.

The method could enable quantum functionalities at temperatures above cryogenic levels.

Abstract

Superconductor based quantum computing has the major drawback of working temperatures which require liquid helium for cooling. A promising approach to overcome this obstacle for quantum technologies is based on deep level defects in semiconductors, with the nitrogen vacancy (NV) center in diamond being the most prominent example. Unfortunately, diamond in sufficient quality is scarce, which motivated efforts to find similar defects in silicon carbide (SiC). So far, many reports focus on investigations of point defects in irradiated 3C-SiC and as grown material. However, the investigated defects are more or less a product of coincidence for both. While in irradiated material the intentional generation of specific defects is rather challenging, in as purchased material the defects are actually more an unintentional by product of growth and process conditions. This work proposes a new route: the incorporation and control of deep level defects in 3C-SiC by epitaxial sublimation growth. The observed defects in the near infrared show bright luminescence in the 175 K/200 K regime and remain excitable up to 300 K. This could enable working temperatures above the cryogenic limit. The joint origin of all detected defects is assigned to the carbon vacancy.