Long-lived NV− spin coherence in high-purity diamond membranes

The electronic spin associated with the nitrogen vacancy (NV) color center in diamond is an excellent candidate for a solid-state qubit functioning as a quantum register or sensor. However, the lack of thin film technologies for crystalline diamond with low impurity levels hampers the development of photonic interfaces to such diamond-based qubits. We present a method for manufacturing slabs of diamond of 200 nm thickness and several microns in extent from high-purity single crystal chemical vapor deposition diamond. We measure spin coherence times approaching 100 μs and observe increased photoluminescence collection from shallow implant NV centers in these slabs. We anticipate these slabs to be appealing as quantum memory nodes in hybrid diamond nanophotonic systems. (paper)