Forefront engineering of nitrogen-vacancy centers in diamond for quantum technologies

Iván Panadero Muñoz

Chunhui Du

Ryota Kuroiwa, Hiroki Kano, Yuhei Sekiguchi +7 more

Kohei Kinouchi, Yasuhiko Shimotsuma, Mitsuharu Uemoto +4 more

Nitrogen-vacancy centers in diamond have gained widespread attention as quantum systems that can be applied in quantum information devices. The excellent properties of quantum devices can be enhanced using preferentially oriented nitrogen-vacancy (NV) centers. However, thus far, orientation control has been achieved only via chemical vapor deposition. In this study, we demonstrate the creation of preferentially oriented NV centers via laser writing. The alignment ratio of ensemble NV centers is biased along the direction parallel to [111], depending on the femtosecond laser polarization, causing an increase of 55% in contrast to the optically magnetic resonance signal at maximum compared with 25% in random orientation. Based on time-dependent density-functional theory (TDDFT) simulations and experimental observations, such complex polarization dependence can be attributed to the anisotropy of electron excitation. This technique provides a new optical fabrication method for engineered materials and devices used in quantum technology.

Yu-Chen Chen, Benjamin Griffiths, Laiyi Weng +11 more

Atomic defects in wide band gap materials show great promise for development of a new generation of quantum information technologies, but have been hampered by the inability to produce and engineer the defects in a controlled way. The nitrogen-vacancy (NV) color center in diamond is one of the foremost candidates, with single defects allowing optical addressing of electron spin and nuclear spin degrees of freedom with potential for applications in advanced sensing and computing. Here we demonstrate a method for the deterministic writing of individual NV centers at selected locations with high positioning accuracy using laser processing with online fluorescence feedback. This method provides a new tool for the fabrication of engineered materials and devices for quantum technologies and offers insight into the diffusion dynamics of point defects in solids.

Phila Rembold, Nimba Oshnik, Matthias M. Müller +3 more

Diamond based quantum technology is a fast emerging field with both scientific and technological importance. With the growing knowledge and experience concerning diamond based quantum systems comes an increased demand for performance. Quantum optimal control (QOC) provides a direct solution to a number of existing challenges as well as a basis for proposed future applications. Together with a swift review of QOC strategies, quantum sensing, and other relevant quantum technology applications of nitrogen-vacancy (NV) centers in diamond, the authors give the necessary background to summarize recent advancements in the field of QOC assisted quantum applications with NV centers in diamond.