Competition and cooperation between the bond change and the frustration in low-dimensional quantum spin systems

我们研究了具有键变化和受挫的一维量子自旋系统。我们处理的模型有：扭曲的钻石型自旋链，等腰三角形自旋管，S=1和S=2交替自旋链，S=1受挫自旋链，有限磁场中自旋隙系统的磁化率和比热反常等。我们使用了精确解、微扰法、数值对角化和密度矩阵重整化群。

We investigated one-dimensional quantum spin systems with bond changes and frustrations. The models we treated were : distorted diamond type spin chain, isosceles triangle spin tube, S=1 and S=2 alternating spin chain, S=1 spin chain with frustrations, anomalies of susceptibility and specific heat of spin gap system in finite magnetic field, and so on. We used the exact solution, perturbation method, numerical diagonalization and density matrix renormalization group.