Diagnostic for phases and quantum critical regions using deviations from the local fluctuation-dissipation theorem
Diagnostic for phases and quantum critical regions using deviations from the local fluctuation-dissipation theorem
复制标题
使用局部涨落耗散定理的偏差诊断相位和量子临界区域
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
N. Trivedi
中科院分区：
文献类型：
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作者：
E. Duchon;Y. Kato;N. Trivedi
光学晶格中的冷原子气体正在成为测试凝聚态物理中强相互作用粒子模型的优秀实验室。目前，一个主要的开放性问题是如何直接从实验中获得给定量子哈密顿量的有限温度相图。以前在这个方向上的工作需要量子蒙特卡罗模拟来直接模拟实验情况，以提取定量信息，这显然违背了光学晶格仿真器的目的。在这里，我们提出了一种新的方法，利用偏差从本地波动耗散定理构建一个有限的温度相图，第一次，从本地可观察到的原位实验观测。我们的方法将涨落耗散定理的实用性从温度测量扩展到量子相位、相关能量标度和量子临界区域的识别。我们使用最先进的大规模量子蒙特卡罗模拟的二维玻色哈伯德模型来测试我们的想法。
Introduction Cold atomic gases in optical lattices are emerging as excellent laboratories for testing models of strongly interacting particles in condensed matter physics. Currently, one of the major open questions is how to obtain the finite temperature phase diagram of a given quantum Hamiltonian directly from experiments. Previous work in this direction required quantum Monte Carlo simulations to directly model the experimental situation in order to extract quantitative information, clearly defeating the purpose of an optical lattice emulator. Here we propose a new method that utilizes deviations from a local fluctuation dissipation theorem to construct a finite temperature phase diagram, for the first time, from local observables accessible by in situ experimental observations. Our approach extends the utility of the fluctuation-dissipation theorem from thermometry to the identification of quantum phases, associated energy scales and the quantum critical region. We test our ideas using state-of-the-art large-scale quantum Monte Carlo simulations of the two-dimensional Bose Hubbard model.