Observation of a four-spin solid effect
Name
5.0091663.pdf
Description
Published version
Size
4.39 MB
Format
Adobe PDF
Checksum (MD5)
253db2a2316ad5655ffd47673d554b2a
Author(s)
Tan, Kong Ooi
Griffin, Robert G
Date Issued
2022
Journal
The Journal of Chemical Physics
Publisher
AIP Publishing
Citation
Tan, Kong Ooi and Griffin, Robert G. 2022. "Observation of a four-spin solid effect." The Journal of Chemical Physics, 156 (17).
Version
Final published version
Abstract
The two-spin solid effect (2SSE) is one of the established continuous wave dynamic nuclear polarization mechanisms that enables enhancement of nuclear magnetic resonance signals. It functions via a state-mixing mechanism that mediates the excitation of forbidden transitions in an electron–nuclear spin system. Specifically, microwave irradiation at frequencies ωμ w ∼ ω0S ± ω0I, where ω0S and ω0I are electron and nuclear Larmor frequencies, respectively, yields enhanced nuclear spin polarization. Following the recent rediscovery of the three-spin solid effect (3SSE) [Tan et al., Sci. Adv. 5, eaax2743 (2019)], where the matching condition is given by ωμ w = ω0S ± 2 ω0I, we report here the first direct observation of the four-spin solid effect (4SSE) at ωμ w = ω0S ± 3 ω0I. The forbidden double- and quadruple-quantum transitions were observed in samples containing trityl radicals dispersed in a glycerol–water mixture at 0.35 T/15 MHz/9.8 GHz and 80 K. We present a derivation of the 4SSE effective Hamiltonian, matching conditions, and transition probabilities. Finally, we show that the experimental observations agree with the results from numerical simulations and analytical theory.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
Francis Bitter Magnet Laboratory (Massachusetts Institute of Technology)
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1063/5.0091663
