  Dynamical nuclear polarisation (DNP) is an important technique that uses
polarisation transfer from electron to nuclear spins to achieve nuclear
hyperpolarisation. As the electron spin of the nitrogen vacancy (NV) centres in
diamond can be optically initialised nearly perfectly even at room temperature
and ambient conditions, new opportunities become possible by the combination of
efficient DNP with optically polarised NV centres. Among such applications are
nanoscale nuclear magnetic resonance spectroscopy of liquids, hyperpolarised
nanodiamonds as MRI contrast agents as well as the initialisation of nuclear
spin based diamond quantum simulators. Current realisations of DNP perform the
polarisation transfer by achieving energetic resonance between electrons and
nuclei via carefully tuned microwave fields or by using quasi-adiabatic
sweep-based schemes across resonance points. The former limits robustness
against control errors while the latter limits polarisation rates, making the
realisation of the applications extremely challenging. Here we introduce the
concept of Hamiltonian engineering by pulse sequences and use it for the
systematic design of polarisation sequences that are simultaneously robust and
fast. We derive sequences theoretically and demonstrate experimentally that
they are capable of efficient polarisation transfer from an optically polarised
nitrogen-vacancy centre in diamond to the surrounding $^{13}$C nuclear spin
bath even in the presence of control errors, making it an ideal tool for the
realisation of the above NV centre based applications.
