Fractional Spin Fluctuations as a Precursor of Quantum Spin Liquids: Majorana Dynamical Mean-Field Study for the Kitaev Model.
Fractional Spin Fluctuations as a Precursor of Quantum Spin Liquids: Majorana Dynamical Mean-Field Study for the Kitaev Model.
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DOI：
10.1103/physrevlett.117.157203
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发表时间：
2016-02
影响因子：
8.6
通讯作者：
Junki Yoshitake;J. Nasu;Y. Motome
中科院分区：
文献类型：
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作者：
Junki Yoshitake;J. Nasu;Y. Motome
量子自旋液体的实验识别仍然是一个挑战，因为原始性质需要在渐近低温下才能看到。我们在这里从理论上证明，量子自旋液体的前体在很宽的温度范围内以顺磁态出现在自旋动力学中。利用马约拉纳费米子表示中新发展的团簇动态平均场理论和连续时间量子蒙特卡罗方法，计算了基态为量子自旋液体典型例子的蜂窝基塔耶夫模型的动态自旋结构因子、核磁共振弛豫率和磁化率。我们发现动态自旋相关性即使在静态相关性饱和的温度以下也表现出特殊的温度和频率依赖性。结果提供了可通过实验获得的波动分数自旋的症状，表明量子自旋液体。
Experimental identification of quantum spin liquids remains a challenge, as the pristine nature is to be seen in asymptotically low temperatures. We here theoretically show that the precursor of quantum spin liquids appears in the spin dynamics in the paramagnetic state over a wide temperature range. Using the cluster dynamical mean-field theory and the continuous-time quantum Monte Carlo method, which are newly developed in the Majorana fermion representation, we calculate the dynamical spin structure factor, relaxation rate in nuclear magnetic resonance, and magnetic susceptibility for the honeycomb Kitaev model whose ground state is a canonical example of the quantum spin liquid. We find that dynamical spin correlations show peculiar temperature and frequency dependence even below the temperature where static correlations saturate. The results provide the experimentally accessible symptoms of the fluctuating fractionalized spins evincing the quantum spin liquids.