Polarizing nuclear spins is of fundamental importance in medicine, biology, chemistry and physics. Universal bulk-hyperpolarization methods are prevented by the need of cryogenic temperatures [1]. Room-temperature approaches with nitrogen-vacancy centers in diamonds still lack large scale applications due to demanding conditions for fine tunings of parameters, e.g. magnetic field strengths and alignments vs. single-crystal diamonds [2].

We report on an approach for achieving efficient electron→nuclear spin polarization transfers, compatible with a broad range of magnetic field strengths and field orientations with respect to the diamond lattice [3]. This versatility results from continuous and simultaneous coherent microwave- and incoherent laser-induced transitions of selected electron-nuclear spin energy-manifolds that polarize the directly electron-coupled nuclei. Nuclear magnetic resonance ¹³C-detected experiments demonstrate that the local hyperpolarization is then extended throughout the nuclear bulk ensemble. This method opens new perspectives on the ensemble and nanoscale applications of these states on NMR/MRI and quantum information processing.

[1] Joo, C.-G., Hu, K.-N., Bryant, J. A. & Griffin, R. G., J. Am. Chem. Soc. 128, 9428–9432 (2006).

[2] R. Fischer, C. Bretschneider, P. London, D. Budker, D. Gershoni, L. Frydman, Phys. Rev. Lett 111, 057601 (2013).

[3] G. A. Alvarez, R. Fischer, C. Bretscneider, P. London, J. Isoya, H. Kanda, S. Onoda, D. Gershoni, L. Frydman (In Preparation).