摘要
本文给出了二维Heisenberg反铁磁系统中的正则变换.在此变换下发现二维Heisenberg反铁磁模型在连续极限下是具有拓扑项的O(3)非线性σ模型.由于在选取正则变量时有很大的不确定性,因此还不能判定此系统是否确有拓扑项存在.最后对正则变换的物理意义进行了研究,发现它体现了系统自旋的集体激发,表明存在着一种自旋波.
The canonical transformation in two dimensional Heisenberg antiferromagnetic system is given in this paper. It is found that under this transformation the 2D Heisenberg antiferromagnetic model is the nonlinear O(3) σ model with a topological term in the continnum limit. Since there exists a large uncertainty when one chooses the canonical variables, it is not completely concluded that whether the topological term really occurs in this system. Finally, the physical meaning of the canonical transformation is also investigated, and it is found that it corresponds to the collective excitations of system spins, i.e., a kind of spin waves exists in this case.
出处
《高能物理与核物理》
CSCD
北大核心
1990年第6期500-503,共4页
High Energy Physics and Nuclear Physics
