Quantum Brilliance, an Australian diamond quantum startup, in conjunction with RMIT University, La Trobe University, and Fraunhofer IAF, has published a paper titled “Bottom-up fabrication of scalable room-temperature diamond quantum computing and sensing technologies.” Appearing in the journal Mater. Quantum Technol., this paper outlines a method for creating and scaling diamond quantum technology by addressing the challenge of precisely fabricating qubits (Nitrogen-Vacancy (NV) centers) in diamond.
The paper proposes the use of atomic scale fabrication (ASF), specifically a hydrogen depassivation lithography (HDL) technique, for the bottom-up fabrication of NV centers. This multi-step procedure is envisioned as a method for deterministic, sub-nanometre spatial precision and the preservation of crystal purity. It involves preparing the diamond substrate and surface, using Scanning Tunneling Microscopy (STM) for imaging and targeted hydrogen desorption to create active adsorption sites, exposing the surface to an N-containing precursor gas for selective chemisorption, and overgrowing using chemical vapor deposition (CVD) to incorporate N into the diamond lattice as NV centers.
This proposed method is intended to enable the realization of integrated diamond quantum devices for room-temperature quantum computing and sensing. For quantum computing, it aims to facilitate arrays of closely-spaced NV centers (e.g., 5–10 nm separation) for two-qubit gate operations. For quantum sensing, it seeks to enhance device sensitivities by enabling scalable production of homogeneous arrays of identical NV centers in a low-noise environment. The authors, including Marcus Doherty, Chief Scientific Officer at Quantum Brilliance, contend that while HDL-based fabrication of NV centers requires engineering, there are no fundamental impediments to its feasibility.
The research identifies key challenges in its development, such as achieving higher spatial accuracy, optimizing N-based molecular adsorption chemistry, and improving N retention and N-to-NV conversion yields during overgrowth. This perspective encourages continued experimental and theoretical progress through sustained community effort and cross-discipline collaboration in the field of atom-scale NV fabrication.
Read more about this research on the Quantum Brilliance newsdesk here and the paper in Mater. Quantum Technol. here.
July 24, 2025
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