Towards diamond light matter quantum interface: development of a multi-qubit quantum register based on paramagnetic color centers in diamond

• Applicant: Professor Dr. Fedor Jelezko
• Subject Area: Experimental Condensed Matter Physics ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 445243414

The problem of creating interconnected over long distance quantum registers remains challenging, despite the considerable efforts of scientific and commercial organizations, including leaders in the market of IT technologies. One of the promising solid-state materials for creating quantum registers is diamond. Qubits in the diamond quantum register is realized by electronic and nuclear spins in the systems. Coherent control of the quantum states of spins is carried out by microwave and radio-frequency fields, and the preparation and reading of states is realized by optical fields acting on the optical transitions of color centers. Historically, the NV center was proposed first as an elementary quantum gate. A key contribution to the development of this direction was made by the project teams from the German and Russian sides. The scientific novelty of this project is to employ new paramagnetic silicon-vacancy color centers in diamonds to create high efficiency quantum registers operating at mK temperatures. The proposed silicon-vacancy color centers have a significantly longer optical coherence time, and their implantation in monolithic diamond resonators will significantly increase the efficiency of the interface of spin qubits with photons when compared to existing technology. At the same time, the proposed studies of new optical centers based on impurities from the fourth group of elements (Ge, Sn, Pb) with inversion symmetry in diamond will lead to possibility to operate quantum registers at higher temperatures of the order of 4K.The project also plans to carry out work in the "traditional" direction of creating quantum registers based on the nitrogen-vacancy color centers. The novelty of the proposed approach lies in the idea of using the so-called "islands of stability" for this - recently discovered positions in the diamond crystal lattice, which provide a high degree of coherence for the spins of isotopic carbon atoms placed in these positions.

• DFG Programme: Research Grants
• International Connection: Belarus, Russia
• Partner Organisation: Russian Science Foundation
• Cooperation Partner: Dr. Alexander P. Nizovtsev