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$Research paper thumbnail of Coherent State Transfer between an Electron and Nuclear Spin in ^{15}N@C_{60}$

Physical Review Letters, 2011

Electron spin qubits in molecular systems offer high reproducibility and the ability to self asse... more Electron spin qubits in molecular systems offer high reproducibility and the ability to self assemble into larger architectures. However, interactions between neighbouring qubits are 'always-on' and although the electron spin coherence times can be several hundred microseconds, these are still much shorter than typical times for nuclear spins. Here we implement an electron-nuclear hybrid scheme which uses coherent transfer between electron and nuclear spin degrees of freedom in order to both controllably turn on/off dipolar interactions between neighbouring spins and benefit from the long nuclear spin decoherence times (T2n). We transfer qubit states between the electron and 15 N nuclear spin in 15 N@C60 with a two-way process fidelity of 88%, using a series of tuned microwave and radiofrequency pulses and measure a nuclear spin coherence lifetime of over 100 ms.

physica status solidi (b), 2006

Nuclear spins have been proposed for the embodiment of quantum information and yielded the most c... more Nuclear spins have been proposed for the embodiment of quantum information and yielded the most complex demonstrations of quantum algorithms to date. However, the weak thermal polarisation of nuclear spins in experimentally accessible conditions has presented a barrier to further scaling. Here, we discuss the benefits of a coupled electron spin to the nuclear spin qubit and demonstrate the ideas using the 14 N nuclear spin in the N@C 60 molecule. In addition to providing a resource for nuclear spin polarisation and detection, the electron spin can be exploited to perform ultrafast nuclear spin phase gates, which can in turn be used to dynamically bang-bang decouple the nuclear spin from unwanted interactions.

The Journal of Chemical Physics, 2005

Electron spin echo envelope modulation (ESEEM) has been observed for the first time from a couple... more Electron spin echo envelope modulation (ESEEM) has been observed for the first time from a coupled hetero-spin pair of electron and nucleus in liquid solution. Previously, modulation effects in spin echo experiments have only been described in liquid solutions for a coupled pair of homonuclear spins in NMR or a pair of resonant electron spins in EPR. We observe low-frequency ESEEM (26 and 52 kHz) due to a new mechanism present for any electron spin with S > 1/2 that is hyperfine coupled to a nuclear spin. In our case these are electron spin (S = 3/2) and nuclear spin (I = 1) in the endohedral fullerene N@C 60 . The modulation is shown to arise from second order effects in the isotropic hyperfine coupling of an electron and 14 N nucleus. * Electronic address: john.morton@materials.ox.ac.uk

physica status solidi (b), 2007

... Arzhang Ardavan *, 1 , John JL Morton 1, 2 , Simon C. Benjamin 2 , Kyriakos Porfyrakis 2 , G.... more ... Arzhang Ardavan *, 1 , John JL Morton 1, 2 , Simon C. Benjamin 2 , Kyriakos Porfyrakis 2 , G. Andrew D. Briggs 2 , Alexei M. Tyryshkin 3 , and SA Lyon 3 1 The Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, UK 2 Department ...