The effect of spin transport on lifetime in nanoscale systems

Spin transport electronics utilizes electron spin as a state variable for information processing and storage. This requires manipulation of spin ensembles for data encoding, and spin transport for information transfer. Here we report spatially resolved magnetic resonance studies of electron spin ensembles confined to a quasi 1D `spin nanowire' formed by nitrogen ion implantation in diamond. We obtain the ensemble spin lifetime, that is, spin autocorrelation time, by measuring statistical fluctuations of the net moment ($\surd $N \textless 100 net spins), which is in thermal equilibrium and has no imposed polarization gradient. We find the lifetime of the ensemble is dominated by spin transport from the ensemble into an adjacent reservoir, which is in striking contrast to conventional spin-lattice relaxation measurements of isolated spin ensembles. In addition, using a novel spin manipulation protocol, we demonstrate spectroscopic measurements on nanoscale spin ensembles that corroborate spin transport in strong field gradients. Our experiments, supported by microscopic Monte Carlo modelling, provide a unique insight into the intrinsic dynamics of charge-motion-free spin currents needed for nanoscale devices which seek to control spins.