Nitrogen-vacancy centres and carbon-13 atoms in carefully grown diamonds can be driven coherently, providing a potential quantum simulator. Carbon-13 nuclear spins in diamond have long coherence times, making them attractive candidates for use as qubits. However, to utilise their advantages they must be incorporated in sufficient numbers into externally-controllable devices. Boris Naydenov of Ulm University with colleagues from Germany, Israel, Switzerland and Japan have fabricated diamond layers made almost entirely from carbon-13 atoms with a high density of nitrogen-vacancy defects. Each NV centre strongly interacts with nearby carbon-13 nuclear spins, allowing the latter to be indirectly controlled using newly developed methods for manipulating small nuclear spin ensembles. The large number of closely spaced qubits could be exploited to simulate models with many interacting two-level systems that are difficult to solve with classical computers.
Unden T, Tomek N, Weggler T, Frank F, London P, Zopes J, Degen C, Raatz N, Meijer J, Watanabe H, Itoh K M, Plenio M B, Naydenov B & Jelezko F