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arXiv · 2607.01441

Resonant cooling of nuclear spins by optically-oriented holes in MAPbI$_3$ perovskite crystals

Mladen Kotur·Dmitri R. Yakovlev·Nataliia E. Kopteva·Bekir Turedi·Maksym V. Kovalenko·Manfred Bayer
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Abstract

Resonant cooling of nuclear spins by photogenerated spin-oriented holes is demonstrated for MAPbI$_3$ perovskite crystals. It is evidenced by Hanle-effect measurements under helicity-modulated excitation with variable frequency. The resonance position in magnetic field shifts toward higher fields with increasing modulation frequency. The invariance of the Hanle curve upon in-plane sample rotation is consistent with the involvement of $^{207}$Pb nuclei with spin $I = 1/2$, which do not exhibit quadrupolar splitting. The shape of the resonance feature in the Hanle curve reveals that the nuclear spins are cooled by carriers with a negative $g$-factor, consistent with holes. The resonance fields associated with the modulation frequencies exceed the half-width of the weakly localized hole contribution to the Hanle curve, indicating that strongly localized holes are the primary carriers responsible for the nuclear spin cooling.

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Mladen Kotur, Dmitri R. Yakovlev, Nataliia E. Kopteva, Bekir Turedi, Maksym V. Kovalenko, Manfred Bayer. 2026-07-01. Resonant cooling of nuclear spins by optically-oriented holes in MAPbI$_3$ perovskite crystals. https://doi.org/10.1021/acs.jpclett.6c02198

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