Ferromagnetism in an Itinerant Electron Cluster
LI Gang ;TIAN Guang-Shan
【期刊名称】《理论物理通讯（英文版）》 【年(卷),期】2005(044)007
【摘要】In the present paper, we study the existence of metallic ferromagnetism in a cluster of nanometer scale,which is described by the Hubbard model defined on a complete graph. Therefore, the system is highly frustrated with respect to electron hopping. By solving the model exactly, we show that its ground state is fully spin-polarized at half-filling, even if the Coulomb interaction is finite. This conclusion is in sharp contrast to the well-known result for the Hubbard model on a bipartite lattice. As a result, our exact solution strongly suggests that frustration may play an important role in causing metallic ferromagnetism.
【总页数】5页(188-192)
【关键词】metallic ferromagnetism;strongly-correlated electron systems;exact solution
【作者】LI Gang ;TIAN Guang-Shan
【作者单位】School of Physics, Peking University, Beijing 100871, China;School of Physics, Peking University, Beijing 100871, China 【正文语种】中文 【中图分类】O4
Ferromagnetism in an Itinerant Electron Cluster
