  The realization of scalable arrangements of nitrogen vacancy (NV) centers in
diamond remains a key challenge on the way towards efficient quantum
information processing, quantum simulation and quantum sensing applications.
Although technologies based on implanting NV-center in bulk diamond crystals or
hybrid device approaches have been developed, they are limited in the
achievable spatial resolution and by the intricate technological complexities
involved in achieving scalability. We propose and demonstrate a novel approach
for creating an arrangement of NV-centers, based on the self-assembling
capabilities of biological systems and its beneficial nanometer spatial
resolution. Here, a self-assembled protein structure serves as a structural
scaffold for surface functionalized nanodiamonds, in this way allowing for the
controlled creation of NV-structures on the nanoscale and providing a new
avenue towards bridging the bio-nano interface. One-, two- as well as
three-dimensional structures are within the scope of biological structural
assembling techniques. We realized experimentally the formation of regular
structures by interconnecting nanodiamonds using biological protein scaffolds.
Based on the achievable NV-center distances of 11nm, we evaluate the expected
dipolar coupling interaction with neighboring NV-center as well as the expected
decoherence time. Moreover, by exploiting these couplings, we provide a
detailed theoretical analysis on the viability of multiqubit quantum
operations, suggest the possibility of individual addressing based on the
random distribution of the NV intrinsic symmetry axes and address the
challenges posed by decoherence and imperfect couplings. We then demonstrate in
the last part that our scheme allows for the high-fidelity creation of
entanglement, cluster states and quantum simulation applications.
