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arXiv 1402.0847cond-mat.stat-mechphysics.comp-phquant-ph
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能隙估计的广义矩方法和量子蒙特卡罗能级谱

Generalized Moment Method for Gap Estimation and Quantum Monte Carlo Level Spectroscopy

Hidemaro Suwa, Synge Todo

摘要:

我们用世界线量子蒙特卡罗方法给出了一个收敛的能隙估计序列。消除了传统量子系统能隙计算中的模糊性。我们的估计在低温极限下是无偏的,误差线也是可靠的。量子蒙特卡罗数据的能级谱作为无偏能隙估计的一个应用。通过光谱分析,我们精确地确定了自旋佩尔斯模型的Kosterlitz-Thouless量子相变点。本文证明了有限频率的量子声子对于由反绝热极限所支配的临界理论是必不可少的,即,$k=1$ SU(2)Wess-Zumino-Witten模型。

英文摘要:

We formulate a convergent sequence for the energy gap estimation in the worldline quantum Monte Carlo method. The ambiguity left in the conventional gap calculation for quantum systems is eliminated. Our estimation will be unbiased in the low-temperature limit and also the error bar is reliably estimated. The level spectroscopy from quantum Monte Carlo data is developed as an application of the unbiased gap estimation. From the spectral analysis, we precisely determine the Kosterlitz-Thouless quantum phase-transition point of the spin-Peierls model. It is stablished that the quantum phonon with a finite frequency is essential to the critical theory governed by the antiadiabatic limit, i.e., the $k=1$ SU(2) Wess-Zumino-Witten model.

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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