arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 0704.1469cond-mat.str-elcond-mat.stat-mech
收藏

价键基量子自旋系统的蒙特卡罗模拟

Monte Carlo Simulations of Quantum Spin Systems in the Valence Bond Basis

A. W. Sandvik, K. S. D. Beach

摘要:

以S=1/2海森堡反铁磁体为例,讨论了价键基量子自旋模型的投影蒙特卡罗方法。它的单重态基态可以从任意基态中投影出来作为试探态,但是使用好的变分态可以获得更快的收敛。作为一种替代方法,首先进行耗时的变分蒙特卡罗计算,我们表明,一个非常好的试验状态可以在模拟过程中产生的迭代方式本身。我们还展示了如何的价键的基础上的属性,使难以获得与Sz本征态的标准基础的数量的计算。特别是,我们讨论的数量涉及有限的动量状态的三重态部门,如色散关系和最低的三重态的光谱重量。

英文摘要:

We discuss a projector Monte Carlo method for quantum spin models formulated in the valence bond basis, using the S=1/2 Heisenberg antiferromagnet as an example. Its singlet ground state can be projected out of an arbitrary basis state as the trial state, but a more rapid convergence can be obtained using a good variational state. As an alternative to first carrying out a time consuming variational Monte Carlo calculation, we show that a very good trial state can be generated in an iterative fashion in the course of the simulation itself. We also show how the properties of the valence bond basis enable calculations of quantities that are difficult to obtain with the standard basis of Sz eigenstates. In particular, we discuss quantities involving finite-momentum states in the triplet sector, such as the dispersion relation and the spectral weight of the lowest triplet.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑