Topological order in the pseudogap metal
Topological order in the pseudogap metal
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DOI：
10.1073/pnas.1720580115
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发表时间：
2017-11
期刊：
影响因子：
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通讯作者：
M. Scheurer;S. Chatterjee;Wéi Wú;M. Ferrero;A. Georges;S. Sachdev
中科院分区：
文献类型：
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作者：
M. Scheurer;S. Chatterjee;Wéi Wú;M. Ferrero;A. Georges;S. Sachdev
意义 氧化铜基高温超导体在低空穴密度状态下，在略高于临界温度的温度下显示出神秘的“赝能隙”金属相。广泛的实验和数值研究已经获得了有关电子校正性质的大量信息，但缺乏基本的理论理解。我们证明，具有拓扑序和涌现规范场的金属理论可以对许多数值数据进行建模。我们的研究为更深入地了解这些超导体中的长程量子纠缠以及直接检测多体量子态的拓扑特征开辟了一条途径。我们计算了方晶格上涨落反铁磁性的 SU(2) 规范理论的拓扑有序希格斯相的电子格林函数。将结果与强相互作用空穴掺杂哈伯德模型的赝能隙相上的动态平均场理论和量子蒙特卡罗计算的簇扩展进行了比较。谱函数和电子自能的动量、频率、跳跃和掺杂依赖性具有良好的一致性。我们证明零频率电子格林函数的（近似）零线是规范理论的基础拓扑顺序的标志，并描述了这些零线如何出现在我们的哈伯德模型理论中。我们还推导了希格斯相中成立的路廷格定理的修改版、非微扰版本。
Significance The copper oxide-based high-temperature superconductors display a mysterious “pseudogap” metal phase at temperatures just above the critical temperature in a regime of low hole density. Extensive experimental and numerical studies have yielded much information on the nature of the electron corrections, but a fundamental theoretical understanding has been lacking. We show that a theory of a metal with topological order and emergent gauge fields can model much of the numerical data. Our study opens up a route to a deeper understanding of the long-range quantum entanglement in these superconductors and to the direct detection of the topological characteristics of the many-body quantum state. We compute the electronic Green’s function of the topologically ordered Higgs phase of a SU(2) gauge theory of fluctuating antiferromagnetism on the square lattice. The results are compared with cluster extensions of dynamical mean field theory, and quantum Monte Carlo calculations, on the pseudogap phase of the strongly interacting hole-doped Hubbard model. Good agreement is found in the momentum, frequency, hopping, and doping dependencies of the spectral function and electronic self-energy. We show that lines of (approximate) zeros of the zero-frequency electronic Green’s function are signs of the underlying topological order of the gauge theory and describe how these lines of zeros appear in our theory of the Hubbard model. We also derive a modified, nonperturbative version of the Luttinger theorem that holds in the Higgs phase.