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PRINCIPAL PUBLICATION AND AUTHORS
The critical role of ultra-low-energy vibrations in the relaxation dynamics of molecular qubits, E. Garlatti (a,b), A. Albino (c), S. Chicco (a), V.H.A. Nguyen (d), F. Santanni (c), L. Paolasini (e), C. Mazzoli (f), R. Caciuffo (g), F. Totti (c), P. Santini (a,b), R. Sessoli (c), A. Lunghi (d), S. Carretta (a,b), Nat. Commun. 14, 1653 (2023); https:/doi.org/10.1038/s41467-023-36852-y (a) Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma and UdR Parma, INSTM, Parma (Italy) (b) INFN, Sezione di Milano- Bicocca, gruppo collegato di Parma, Parma (Italy) (c) Dipartimento di Chimica Ugo Schiff , Università Degli Studi di Firenze and UdR Firenze, INSTM, Sesto Fiorentino (Italy) (d) School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2 (Ireland) (e) ESRF (f) National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY (USA) (g) INFN, Sezione di Genova, Genova (Italy)
REFERENCES
[1] A. Chiesa et al., J. Phys. Chem. Lett. 11, 8610−8615 (2020). [2] S. Chicco et al., Chem. Sci. 12, 12046 (2021) [3] A. Lunghi, Appl. Magn. Reson. 51, 1343 (2020).
provided a complete picture of phonon-induced relaxation and decoherence. By performing a neural network-based interpolation of the DFT calculations to estimate the spin- phonon couplings coefficients [3], it was shown that low-energy optical phonons in [VO(TPP)] possess very strong couplings (Figure 58a) and are crucial in magnetic relaxation up to ambient temperature (Figure 58b). By inspecting the nature of the relevant phonons for spin relaxation (Figure 58c), it was also possible to provide a chemical strategy for tailoring the intramolecular motions in [VO(TPP)] and thus slowing down relaxation.
These results demonstrate that the synergistic combination of the IXS technique with pDFT spin dynamics simulations is able to yield unprecedented insight into the nature of phonons and vibrations, as well as their role in magnetic relaxation and decoherence of molecular qubits.
Fig. 58: a) Spin-phonon coupling coefficients calculated as a function of the frequency of the vibration (red line) compared to vibrational density of states (black line) of [VO(TPP)]. b) Computed spin-phonon relaxation time T1 (red line-full squares) and coherence time T2 (inset, continuous green line-empty squares). The blue line-filled triangles represent the simulated T1 after removal of all low-energy phonons. Black full (empty) circles are used to report the inversion recovery (Hahn echo) experimental data on [VO(TPP)]. c) Molecular distortions associated with the first optical mode at the Γ-point (red, orange) compared with the equilibrium molecular structure (yellow). Reprinted with permission from E. Garlatti et al., Nat. Commun. 14, 1653 (2023), under a Creative Commons Attribution 4.0 International License.
