摘要
从自旋波理论出发,通过直接求解Heisenberg模型,研究了低温下小粒子自旋体系的自发磁化规律。研究表明:极低温下自旋波被冻结;在任何温度范围内,Bloch T^(3/2)定律都不再严格成立。同时,本文还给出了小粒子中自旋受激反转几率随位置的分布,指出低温下不存在运动明显剧烈的表面层。
Based upon the spin wave theory, the spontaneous magnetization of small particle system at low temperatures is studied by means of solving the Heisenberg model directly. Investigations show that the spin waves are frozen out at ultra-low temperature, and the Bloch T3/2 law is no longer correct in any region of temperature. At the same time, the distribution of the probability for spins to be activated versus positions is obtained, which indicates that there exists no spin layers with obviously high probability to flip.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1993年第1期134-141,共8页
Acta Physica Sinica
基金
国家自然科学基金
关键词
小粒子体系
自旋波
磁化
低温
Elementary particles
Ferromagnetism
Paramagnetism
