I will present the development of electron and nuclear spin hyperpolarization techniques and their applications in dynamic nuclear polarization (DNP) and quantum sensing.

With an improved understanding of the spin dynamics of chirped pulsed DNP [1], we performed experiments using the 94 GHz HiPER (High Power quasi-optical EPR) spectrometer located at the National High Magnetic Field Laboratory. Using chirped pulses, the polarization transfer efficiency can be optimized and a record enhancement ε ∼ 496 was observed using trityl-OX063 radical as the polarizing agent [2]. We believe that our experimental results at W-band are a strong evidence that coherent pulsed DNP methods should be further developed at higher magnetic fields, where the NMR resolution can be yielded. Therefore, we are currently constructing a 263 GHz pulsed DNP spectrometer to enable high-field coherent DNP studies. We apply these DNP approaches to investigate the adsorption of per- and polyfluoroalkyl substances (PFAS) in metal-organic frameworks (MOFs), enabling site-specific characterization of host-guest interactions with improved sensitivity.

Instead of relying on stable radicals, hyperpolarization of nuclear spins can also be achieved using photoexcited transient triplet states of pentacene molecules. This photo-addressability holds significant potential for quantum information science (QIS), inspiring us to explore the coherent control of these molecular spins through optical initialization and detection. We achieve full three-dimensional microwave field reconstruction by detecting the Rabi frequencies of anisotropic spin-triplet transitions associated with two crystallographic orientations of pentacene in naphthalene crystals [3]. These results establish pentacenebased molecular spins as a practical and high-performance platform for microwave quantum sensing.

[1] Y. Quan, J. Steiner, Y. Ouyang, K. O. Tan, W. T. Wenckebach, P. Hautle, and R. G. Griffin, The Journal of Physical Chemistry Letters 0, 5751 (2022).

[2] Y. Quan, M. V. H. Subramanya, Y. Ouyang, M. Mardini, T. Dubroca, S. Hill, and R. G. Griffin, The Journal of Physical Chemistry Letters 14, 4748 (2023).

[3] B. Li, G. Heller, J. Yoon, A. Ungar, H. Tang, G. Wang, P. Hautle, Y. Quan, and P. Cappellaro, https://arxiv.org/pdf/2512.06272 (2026).