2005/01/05 by D. A. Garanin, R. Schilling · 2 citations
Chemistry · Materials Science · Physics and Astronomy · #Advanced NMR Techniques and Applications #Atomic physics #Condensed matter physics #Coupling (piping) #Dipole #Lanthanide and Transition Metal Complexes #Magnetism in coordination complexes #Materials science #Physics #Quantum mechanics #Quantum tunnelling #Range (aeronautics) #Resonance (particle physics) #Spins #Thermodynamics #Voltage #Yield (engineering) #Zener diode #cond-mat.mtrl-sci #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevb.71.184414
published as Phys. Rev. B 71, 184414 -(14) (2005) · 14 PR pages, 8 Figures
arxiv created 2005/01/05 · openalex publication_date 2005/05/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The asymptotic staying probability P in the Landau-Zener effect with interaction is analytically investigated at fast sweep \ensuremathε=\ensuremathπ\ensuremathΔ2∕(2\ensuremathℏv)⪡1. We have rigorously calculated the value of I0 in the expansion P\ensuremath≅1\ensuremath-\ensuremathε+\ensuremathε2∕2+\ensuremathε2I0 for arbitrary couplings and relative resonance shifts of individual tunneling particles. The results essentially differ from those of the mean-field approximation. It is shown that strong long-range interactions such as dipole-dipole interaction generate huge values of I0 because a flip of one particle strongly influences many others. However, in the presence of strong static disorder, making the resonances for individual particles shifted with respect to each other, the influence of interactions is strongly reduced. In molecular magnets the main source of static disorder is the coupling to nuclear spins. Our calculations using the actual shape of the Fe8 crystal studied in the Landau-Zener experiments [Wernsdorfer et al., Europhys. Lett. 50, 552 (2000)] yield a value of I0 that is in good agreement with the value extracted from the experimental data.