Mesoscopic Stoner Instability
摘要
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.
引用
@article{arxiv.cond-mat/0004205,
title = {Mesoscopic Stoner Instability},
author = {I. L. Kurland and I. L. Aleiner and B. L. Altshuler},
journal= {arXiv preprint arXiv:cond-mat/0004205},
year = {2007}
}
备注
19 pages, 6 figures