In this part of the review, the currently implemented elementary quantum algorithms are considered and prospects of the development of the full-scale quantum computer based on NV centers in diamond are discussed. The NV-hybrid systems, which can operate as the communication elements between remote NV qubits, are analyzed.
We discuss how Very Large Scale Integration (VLSI) fabrication techniques can be used to build scalable solid-state quantum computers in diamond with either room temperature operation, or low temperature operation with photonic control. For this discussion we consider nitrogen-vacancy (NV) color centers where the qubits are electron and/or nuclear spins. To achieve scalability the NV centers are placed in well-defined locations using ion implantation, and are controlled using optical and/or microwave excitation as well as localized static electric and/or magnetic fields.
In this study, the main results of experimental and theoretical investigations that substantiate the possibility of the development of quantum computational systems with a separate structure are considered and analyzed. These systems involve the operational part and the memory, as well as the communication quantum network, which performs the data exchange between them. We are starting to get knowledge about such hybrid quantum devices from studying the solid-state systems, in which the macroscopic number (ensemble) of NV centers in diamond is used as the memory element, while superconducting mesoscopic structures play the role of the operational element and quantum network.
Quantum computers have the potential to speed up certain problems that are hard for classical computers. Hybrid systems, such as the nitrogen-vacancy (NV) center in diamond, are among the most promising systems to implement quantum computing, provided the control of the different types of qubits can be efficiently implemented. In the case of the NV center, the anisotropic hyperfine interaction allows one to control the nuclear spins indirectly, through gate operations targeting the electron spin, combined with free precession. Here, we demonstrate that this approach allows one to implement a full quantum algorithm, using the example of Grover's quantum search in a single NV center, whose electron is coupled to a carbon nuclear spin.
Artificial atoms like the nitrogen vacancy (NV) centers in diamond enable the realization of fully functional qubits in a solid at room temperature. The functionalities of all the parts needed to create a quantum computer, such as quantum error correction, couplings, quantum teleportation, and a quantum repeater, have already been experimentally demonstrated. These achievements are expected to influence the industrial development of quantum information technology as well as quantum sensing. Whereas quantum sensing has been established and a large number of organizations are working on new developments in this area, a quantum computer itself remains elusive due to technical reasons and limitations of the available materials. For example, only in recent months has it become possible to electrically readout the NV spin state at the level of a single center and significantly improve the scalability of NV center production. A number of ideas have been proposed to overcome the above-mentioned limitations. This paper summarizes the status of research in the area, details the most promising concepts for development, and discusses factors limiting progress as well as the most recent developments in the field.