Universal Conductivity in a Two-Dimensional Superfluid-to-Insulator Quantum Critical System
Universal Conductivity in a Two-Dimensional Superfluid-to-Insulator Quantum Critical System
复制标题
二维超流体到绝缘体量子临界系统中的通用电导率
DOI：
10.1103/physrevlett.112.030402
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发表时间：
2014-01-23
影响因子：
8.6
通讯作者：
Prokof'ev, Nikolay
中科院分区：
文献类型：
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作者：
Chen, Kun;Liu, Longxiang;Prokof'ev, Nikolay
我们计算了（2 + 1）维XY普适类的普适电导率，这是实现了超流到莫特绝缘体量子相变在恒定密度。基于经典的（2 + 1）维J电流模型和二维玻色-哈伯德模型的大规模Monte Carlo模拟，我们可以精确地确定量子临界平台上的电导率，σ（无穷大）= 0.359（4）σ（Q），其中σ（Q）是电导率量子。普适电导率曲线是一个标准的例子，它具有最少的分量数，在这里弦理论自下而上的AdS/CFT对应可以被检验和使用[R. C.迈尔斯，S. Sachdev和A. Singh，Phys.Rev.D83，066017（2011）]。这是第一次，在松原表示的sigma（iw（n））- sigma（无穷大）函数的形状是足够准确的结论性比较，并建立了粒子性质的电荷传输。我们发现，如果黑膜视界的温度与共形场论的温度不同，则输运性质的全息规范-引力对偶理论可以与数据相容。通过计算还确定了在冷气体实验中测量普适电导率的要求。
We compute the universal conductivity of the (2 + 1)-dimensional XY universality class, which is realized for a superfluid-to-Mott insulator quantum phase transition at constant density. Based on large-scale Monte Carlo simulations of the classical (2 + 1)-dimensional J-current model and the two-dimensional Bose-Hubbard model, we can precisely determine the conductivity on the quantum critical plateau, sigma(infinity) = 0.359(4)sigma(Q) with sigma(Q) the conductivity quantum. The universal conductivity curve is the standard example with the lowest number of components where the bottoms-up AdS/CFT correspondence from string theory can be tested and made to use [R. C. Myers, S. Sachdev, and A. Singh, Phys. Rev. D 83, 066017 (2011)]. For the first time, the shape of the sigma(iw(n)) - sigma(infinity) function in the Matsubara representation is accurate enough for a conclusive comparison and establishes the particlelike nature of charge transport. We find that the holographic gauge-gravity duality theory for transport properties can be made compatible with the data if temperature of the horizon of the black brane is different from the temperature of the conformal field theory. The requirements for measuring the universal conductivity in a cold gas experiment are also determined by our calculation.