Fig. 3

Distance dependence of the spin lifetime. a Mean lifetimes of the data recorded on the trimer \(\tau _{\mathrm{t}}\) (black) and on the atom \(\tau _{\mathrm{a}}\) (red) in dependence of the trimer−atom separation (Note, that the lifetimes for the separation corresponding to the configuration in Fig. 1a differ from those in Fig. 1b due to a different measurement voltage, V = −5 mV, I = 500 pA, B = 0 T and T = 300 mK). Data points of the complexes with an fcc (hcp) adsorbed satellite atom are marked with a circle (star). The horizontal (vertical) dashed line marks the lifetime of the free-standing trimer (the crossover between the two lifetime regimes). In gray (weak red) the simulated lifetimes for the scenario of the tip probing the trimer (the satellite atom) are given. b Calculated lifetimes probed on the trimer for the experimental separations using different parts of the exchange interactions. The reference data using the full exchange interactions are shown in gray. The lifetimes calculated without the symmetric anisotropic exchange are shown in green. The lifetimes calculated without the DM interaction are shown in purple. c Calculated lifetimes probed on the trimer in dependence of the isotropic exchange interaction J_iso (AFM: green, FM: purple) and the DM interaction D_x (blue). For the calculations, the two remaining exchange contributions are set to zero (Supplementary Note 7). The gray area marks the regime of the exchange constants found for an atom−trimer separation of about 1.25 nm