Sign-Problem-Free Quantum Monte Carlo of the Onset of Antiferromagnetism in Metals
Sign-Problem-Free Quantum Monte Carlo of the Onset of Antiferromagnetism in Metals
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DOI：
10.1126/science.1227769
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发表时间：
2012-12-21
期刊：
影响因子：
56.9
通讯作者：
Sachdev, Subir
中科院分区：
文献类型：
--
作者：
Berg, Erez;Metlitski, Max A.;Sachdev, Subir
金属反铁磁性的量子理论对于我们理解许多广泛关注的金属间化合物是必要的。在这些系统中，随着外部参数（如化学掺杂）的变化，量子临界点出现。由于该临界点的强耦合性质以及困扰数值量子蒙特卡罗（QMC）方法的“符号问题”，对其理论认识尚不完整。在这里，我们证明了金属中反铁磁性起始的通用低能理论可以在晶格模型中实现，该模型不存在符号问题，因此可以有效地用QMC进行模拟。我们的模拟显示了费米表面重建和跨越临界点的非常规自旋单重态超导性。
The quantum theory of antiferromagnetism in metals is necessary for our understanding of numerous intermetallic compounds of widespread interest. In these systems, a quantum critical point emerges as external parameters (such as chemical doping) are varied. Because of the strong coupling nature of this critical point and the "sign problem" plaguing numerical quantum Monte Carlo (QMC) methods, its theoretical understanding is still incomplete. Here, we show that the universal low-energy theory for the onset of antiferromagnetism in a metal can be realized in lattice models, which are free from the sign problem and hence can be simulated efficiently with QMC. Our simulations show Fermi surface reconstruction and unconventional spin-singlet superconductivity across the critical point.