Researchers, including Prof. Cyril Popov from the University of Kassel, developed a method to fabricate high-quality thin single-crystal diamond (SCD) membranes with very low surface roughness, around 0.2 nm. These membranes are crucial for quantum information technologies and nanophotonics, where surface quality is key. The study highlights the importance of high-quality starting materials, effective cleaning processes, and precise etching techniques.

The collaboration with Qnami Quantum Foundry played a significant role in achieving the desired low-defect membranes, which were successfully tested in Fabry–Pérot microcavities for their optical properties.