玻色气体的磁性

物质磁性一直是凝聚态物理研究的重要课题.以往对磁性的探索主要是以费米子（局域或巡游的电子）为研究对象.由于传统的玻色系统液氦没有自旋，不表现磁性，玻色系统的磁性很少被关注.碱金属原子气体玻色-爱因斯坦凝聚的实现，在开辟了冷原子物理研究领域的同时，也打开了研究玻色系统磁性的大门.这是因为碱金属原子通常具有超精细结构，是旋量玻色气体，能够展示磁性.文章通过对比费米气体的相关结果，介绍了旋量玻色气体磁性的研究概况和最新进展，特别是铁磁性玻色气体的磁性相变以及在低温下铁磁性凝聚体的动力学特征.

Magnetism of Bose gases

The magnetism of Fermi gases and local magnetic moments has long been a key research topic in condensed matter physics, while that of Bose gases has historically been less studied. The reason for this may be due to the fact that He-4, the prototypical Bose system studied in earlier years, is a system of scalar particles and does not display magnetism at all. The realization of Bose-Einstein condensation in alkali atoms opens up a way to study magnetism in spinor bosons, because these constituent atoms usually have a hyperfine spin degree of freedom. This paper will review our current understanding of magnetism in Bose gases, especially focusing on new results obtained regarding ferromagnetic transitions in spinor bosons and the spin dynamics of spinor condensates.