摘要翻译：
电荷、自旋和轨道自由度是过渡金属化合物的物理基础。许多工作已经揭示了许多这些系统中与自旋和电荷自由度相关的量子临界点。在这里，我们说明了体现轨道自由度的最简单模型--二维和三维量子轨道罗盘模型--在稀释的正方形和立方晶格（掺杂分数分别为1/4和1/2）上表现出精确的量子临界行为。这就增加了在掺杂（或施加压力）这种过渡金属体系时，由于轨道有序退化而触发量子临界点的可能性。在几个相关的系统中，我们证明了轨道耦合为非均匀的轨道自旋玻璃的存在性。此外，在单轴压力作用下，还预测了一个新的轨道Larmor进动（即轨道状态的周期性变化）。
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英文标题：
《Orbital order driven quantum criticality》
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作者：
Zohar Nussinov, Gerardo Ortiz
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最新提交年份：
2008
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分类信息：

一级分类：Physics        物理学
二级分类：Strongly Correlated Electrons        强关联电子
分类描述：Quantum magnetism, non-Fermi liquids, spin liquids, quantum criticality, charge density waves, metal-insulator transitions
量子磁学，非费米液体，自旋液体，量子临界性，电荷密度波，金属-绝缘体跃迁
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一级分类：Physics        物理学
二级分类：Statistical Mechanics        统计力学
分类描述：Phase transitions, thermodynamics, field theory, non-equilibrium phenomena, renormalization group and scaling, integrable models, turbulence
相变，热力学，场论，非平衡现象，重整化群和标度，可积模型，湍流
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英文摘要：
  Charge, spin, and orbital degrees of freedom underlie the physics of transition metal compounds. Much work has revealed quantum critical points associated with spin and charge degrees of freedom in many of these systems. Here we illustrate that the simplest models that embody the orbital degrees of freedom - the two- and three-dimensional quantum orbital compass models - exhibit an exact quantum critical behavior on diluted square and cubic lattices (with a doping fraction of 1/4 and 1/2 respectively). This raises the possibility of quantum critical points triggered by the degradation of orbital order upon doping (or applying pressure to) such transition metal systems. We prove the existence of an orbital spin glass in several related systems in which the orbital couplings are made non-uniform. Moreover, a new orbital Larmor precession (i.e., a periodic change in the orbital state) is predicted when uniaxial pressure is applied.
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PDF链接：
https://arxiv.org/pdf/801.4391