New breakthrough brings diamond-based quantum internet closer to reality

Researchers at Humboldt-Universität zu Berlin have made a significant breakthrough in advancing diamond-based quantum communication networks by developing a new method to generate single photons using ultrafast laser pulses. Their study focuses on diamond crystals containing tin vacancy centers (SnV centers), atomic defects that act as stable quantum bits (qubits) capable of storing and processing quantum information while coupling it to photons. The novel approach overcomes previous challenges in controlling qubits with light and detecting emitted photons efficiently, which were hindered by complex filtering techniques that limited system scalability. The team’s method, called SUPER, uses ultrafast pulses to control the quantum state on unprecedented time scales, enabling faster and more complex quantum operations. Importantly, SUPER preserves the internal quantum spin state, a critical factor for generating quantum entanglement between distant nodes—an essential feature for future quantum communication networks. By combining diamond nanostructure fabrication, ultrafast optical technologies, and theoretical modeling, the researchers demonstrated a powerful new tool for solid