Ab Initio Formation Energy Calculations for Defect Complexes in Diamond, ZnSe and CdS for Room-Temperature Quantum Computing

Quantum computers are beginning to demonstrate a potential for practical uses in data security, protein folding, artificial intelligence and machine learning, and economics. Current obstacles to reliable large-scale quantum computers include better decoherence times, improved error correction schemes, and consistent fabrication. Creating a qubit (quantum bit) that can exist at room temperature makes large progress in each of these obstacles while decreasing operational costs (by eliminating the need for cryogenic cooling). Diamond has shown promising results when a defect known as the Nitrogen Vacancy (NV) complex is introduced via doping into the crystal. However, diamond is expensive to fabricate and foundries that can do so are rare. ZnSe and CdS, by contrast, can be grown at lower temperatures and pressures than diamond, and do not require the expensive retooling of foundries for the higher pressure and temperature required in diamond fabrication. This study provides a methodology and computational structure with which to identify semiconductors with similar desirable electronic properties as the NV defect in diamond and identifies potential defects for the two specified semiconductors of interest. This work may guide experimental exploration of quantum technologies based on semiconductor defects and could lead to lower cost, room-temperature qubits that are easily fabricated using the vast infrastructure of the current semiconductor industry.