Browsing by Subject "NV centers"

The NV⁻ center is an optically active defect consisting of a nitrogen atom next to a vacancy with a trapped electron. The defect is ideally suited for many quantum applications and thanks to its long coherence time at elevated temperatures, it can be used as quantum bits for quantum information processing even at room temperature. The defect is found in diamond, which is an exemplary host to a wide range of optically active defects due to its unique properties. As nitrogen is the most common impurity in diamond, NV centers occur naturally but at concentrations that are often deemed insufficient for applications. Thus, understanding the formation process of NV centers and how to efficiently produce them with high spatial resolution is of great interest. In this thesis, the formation of NV centers through irradiation has been studied both in the nuclear and electronic stopping power regimes with molecular dynamics. The analysis of the atomic configurations and displacement resulting from the irradiation revealed two different formation mechanisms, in which either a carbon vacancy is created next to a nitrogen atom or a nitrogen atom becomes mobile to be trapped by a vacancy. While the probability of NV formation from irradiation alone was shown to be low in the nuclear regime, two-temperature molecular dynamics simulations of swift heavy ions in the electronic regime showed the direct formation of NV-centers along the ion’s path. By producing NV centers along an almost one dimensional chain, swift heavy ions offer high spatial resolution in addition to high conversion rates from nitrogen to NV centers due to their high energies.