2003/02/05 by D. A. Garanin
Chemistry · Materials Science · Physics and Astronomy · #Advanced NMR Techniques and Applications #Magnetism in coordination complexes #Quantum and electron transport phenomena #cond-mat.mtrl-sci #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevb.68.014414
published as Phys. Rev. B 68, 014414 (2003) · 13 PR pages, 15 Figs
arxiv created 2003/02/05 · openalex publication_date 2003/07/11 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The Landau-Zener-Stueckelberg (LZS) effect in a model system of interacting tunneling particles is studied numerically and analytically. Each of N tunneling particles interacts with each of the others with the same coupling J. This problem maps onto that of the LZS effect for a large spin S=N/2. The mean-field limit \stackrel\ensuremath→N\ensuremath∞ corresponds to the classical limit \stackrel\ensuremath→S\ensuremath∞ for the effective spin. It is shown that the ferromagnetic coupling J>0 tends to suppress the LZS transitions. For \stackrel\ensuremath→N\ensuremath∞ there is a critical value of J above which the staying probability P does not go to zero in the slow sweep limit, unlike the standard LZS effect. For J<0 LZS transitions are boosted and P=0 for a set of finite values of the sweep rate for \stackrel\ensuremath→N\ensuremath∞. Various limiting cases such as strong and weak interaction, slow and fast sweep are considered analytically. It is shown that the mean-field approach works well for arbitrary N if the interaction J is weak.