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Q: Fachverband Quantenoptik und Photonik
Q 63: Quanteninformation: Quantencomputer
Q 63.4: Vortrag
Freitag, 6. März 2009, 14:45–15:00, VMP 6 HS-A
Dynamic polarization of single nuclear spins in a room temperature diamond — •Philipp Neumann, Vincent Jacques, Johannes Beck, Fedor Jelezko, and Jörg Wrachtrup — 3. Physikalisches Institut, Universität Stuttgart, Germany
Recently, room temperature readout of single nuclear spins in diamond has been achieved by coherently mapping nuclear spin states onto the electron spin of a single NV color center. This has been the basis for spectacular experiments in quantum information science, ranging from the implementation of a nuclear-spin-based quantum register, a conditional two-qubit CNOT gate and recently the generation of Bell and GHZ states with extraordinarily long coherence times.
However, most of these experiments were performed without any deterministic polarization of nuclear spin states. This random initialization unavoidably decreases the success rate of all local operations as 1/2N where N is the number of qubits.
We report a versatile method to efficiently polarize single nuclear spins in diamond, which is based on optical pumping of a single NV color center and mediated by a level-anti crossing in its excited state. A nuclear spin polarization higher than 98% is achieved at room temperature for the 15N nuclear spin associated to the NV center. Furthermore we show simultaneous deterministic initialization of two nuclear spins (13C and 15N) close to a NV defect, which provides efficient initialization of a three qubit quantum register including the electron spin. Such robust control of nuclear spin states is a key ingredient for further scaling up nuclear-spin based quantum registers in diamond.