Berlin 2024 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 71: Many-Body Quantum Dynamics I (joint session DY/TT)

TT 71.2: Vortrag

Donnerstag, 21. März 2024, 09:45–10:00, A 151

Understanding NMR signals by cluster dynamic mean-field theory — •Timo Gräßer¹, Thomas Hahn², and Götz S. Uhrig¹ — ¹Condensed Matter Theory, TU Dortmund University, Otto-Hahn Straße 4, 44221 Dortmund, Germany — ²School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, United Kingdom

A recently developed dynamic mean-field theory for spins at infinite temperature (spinDMFT)[1] is used to understand NMR signals quantitatively. The underlying idea is to couple a spin to a dynamic Gaussian mean-field with second moments that are self-consistently linked to the spin's autocorrelations. We improve the approach by considering clusters of spins quantum-mechanically (CspinDMFT)[2]. The extended model is more accurate and it allows for computing multi-spin correlations. We show that generic NMR signals comprise contributions of such multi-spin correlations. The applicability and validity of this approach is shown by describing NMR data for calcium fluoride (Ca F2) and adamantane (C10 H16).

[1] T. Gräßer et al., Phys. Rev. Research 3, 043168 (2021).

[2] T. Gräßer et al., arXiv:2307.14188 (2023).

Keywords: Dynamic mean-field theory; Spin systems; Nuclear Magnetic Resonance; Many-body correlations