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arXiv 1504.01334cond-mat.str-el
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反铁磁J_{1} - J_{2}海森堡模型的磁量子相变

Magnetic quantum phase transitions of the antiferromagnetic J_{1}-J_{2} Heisenberg model

T. P. Cysne, M. B. Silva Neto

摘要:

在$O(N)$非线性sigma模型的框架下,我们得到了反铁磁$J_{2}$模型$0\leq α= J_2/J1 \leq 1$的完整相图.发现$α\leq 0.4$和$α\geq 0.6$存在两个磁有序相,一个是N 'eel有序相,另一个是共线有序相,两个磁有序相被一个带隙区隔开,而$0.4\leq α\leq 0.6$存在带隙的自旋液体.我们的结果在$N\rightarrow\infty$处是精确的,并且与不同方法的数值结果一致。

英文摘要:

We obtain the complete phase diagram of the antiferromagnetic $J_{1}$-$J_{2}$ model, $0\leq α= J_2/J1 \leq 1$, within the framework of the $O(N)$ nonlinear sigma model. We find two magnetically ordered phases, one with N\' eel order, for $α\leq 0.4$, and another with collinear order, for $α\geq 0.6$, separated by a nonmagnetic region, for $0.4\leq α\leq 0.6$, where a gapped spin liquid is found. The transition at $α=0.4$ is of the second order while the one at $α=0.6$ is of the first order and the spin gaps cross at $α=0.5$. Our results are exact at $N\rightarrow\infty$ and agree with numerical results from different methods.

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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