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arXiv 1102.1819cond-mat.str-el
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用玻色RVB波函数研究双层Heisenberg模型的量子相变

Variational study of the quantum phase transition in bilayer Heisenberg model with Bosonic RVB wave function

Haijun Liao, Tao Li

摘要:

本文用玻色RVB波函数研究了正方格子上双层海森堡模型的基态相图。该波函数具有Gutzwiller投影Schwinger玻色子平均场基态的形式,并涉及两个变分参数。我们发现波函数在量子相变的两边都提供了系统的精确描述。特别是通过对自旋结构因子、基态保真度磁化率和束缚矩比$Q_{2}$的分析,发现在$α_{c}=J_{\perp}/J_{\parallel}\approx2.62$的临界耦合处存在从反铁磁有序态到量子无序态的连续跃迁,与量子蒙特卡罗模拟的结果一致.由有限尺寸标度分析($1/ν\approx1.4$)得到的临界指数与经典的3D海森堡普适类的临界指数一致。

英文摘要:

We study the ground state phase diagram of the bilayer Heisenberg model on square lattice with a Bosonic RVB wave function. The wave function has the form of a Gutzwiller projected Schwinger Boson mean field ground state and involves two variational parameters. We find the wave function provides an accurate description of the system on both sides of the quantum phase transition. Especially, through the analysis of the spin structure factor, ground state fidelity susceptibility and the Binder moment ratio $Q_{2}$, a continuous transition from the antiferromagnetic ordered state to the quantum disordered state is found at the critical coupling of $α_{c}=J_{\perp}/J_{\parallel}\approx2.62$, in good agreement with the result of quantum Monte Carlo simulation. The critical exponent estimated from the finite size scaling analysis($1/ν\approx1.4$) is consistent with that of the classical 3D Heisenberg universality class.

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。

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