Hannover 2016 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 47: Quantum Information: Quantum Computing and Communication I

Q 47.1: Talk

Thursday, March 3, 2016, 11:00–11:15, e214

Germanium vacancy centres and the "smart search" for perfect diamond qubits — •Lachlan J. Rogers and Fedor Jelezko — Institute for Quantum Optics and IQST, Ulm University, Ulm, Germany

Colour centres in diamond are attractive qubit architectures, but the currently available candidates are not perfect. The nitrogen vacancy (NV) centre is famous as an optically addressable electron- and nuclear-spin qubit. However, the NV fluorescence spectrum exhibits a number of undesirable characteristics including a strong phonon sideband and, typically, spectral diffusion of the zero-phonon line (ZPL). More recently the related silicon vacancy (SiV) centre has been shown to have exceptional optical properties, but a fundamentally limited spin coherence time of only 40 ns.

While it is possible to search randomly for attractive spin properties among other reported colour centres, the development in understanding NV and SiV centres over the last decade has begun to enable a "smart search". Here we present germanium vacancy centres as an example of this process. There is a tantalising possibility that germanium vacancies could combine the excellent spin coherence properties of NV with the superb spectral properties of SiV, leading to an almost perfect diamond qubit.