2000/04/12 by I. L. Kurland, I. L. Aleiner, Kurland, I. L. +4
Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Theoretical and Computational Physics #cond-mat.mes-hall
paper · pdf · doi:10.48550/arxiv.cond-mat/0004205
19 pages, 6 figures
arxiv created 2000/04/12 · openalex publication_date 2000/04/12 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The paper is devoted to the magnetic properties of isolated mesoscopic grains. We demonstrate that under very general conditions the electron - electron interactions in such grains can be taken into account by a simple interaction Hamiltonian. This Hamiltonian involves only three coupling constants which correspond to charging, exchange interaction, and superconducting correlations. The most important condition for such a description is that Thouless conductance of each grain is large. Under this condition sample-to-sample fluctuations of the coupling constants can be neglected. However, the thermodynamic properties can still remain sample-specific due to the one-electron part of the Hamiltonian. If the grain is made from a material which is close to the threshold of ferromagnetic instability the mesoscopic fluctuations of the magnetization are especially strong. Moreover, the situation becomes multi-stable: free energy of each grain as a function of the magnetization is characterized by a large number of local minima. We analyze the statistics of these minima and show that it possesses simple scaling properties. Numerical simulations confirm this scaling.