Large Fermi Surface of Heavy Electrons at the Border of Mott Insulating State in NiS2.
Large Fermi Surface of Heavy Electrons at the Border of Mott Insulating State in NiS2.
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DOI：
10.1038/srep25335
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发表时间：
2016-05-12
影响因子：
4.6
通讯作者：
Grosche FM
中科院分区：
文献类型：
--
作者：
Friedemann S;Chang H;Gamża MB;Reiss P;Chen X;Alireza P;Coniglio WA;Graf D;Tozer S;Grosche FM
量子物理学的一个早期胜利是解释了为什么有些材料是金属的，而另一些是绝缘的。虽然基于单电子状态的处理对大多数材料是正确的，但当电子之间的静电排斥引起强相关性时，这种方法可能会失败。这些不仅有利于新的和微妙的物质形式，如磁性或超导性，它们甚至可以导致半满能带中的电子锁定在位置上，产生相关或莫特绝缘体。向莫特绝缘态的转变提出了重要的基本问题。其中最重要的是命运的电子费米面和相关的电荷载流子质量，作为莫特过渡的办法。我们报告的第一个直接观察费米表面的金属一侧的莫特绝缘过渡高压量子振荡测量NiS 2。我们的结果指出，在一个大的费米面与Luttinger的定理和一个强烈增强的准粒子有效质量一致。这两个发现是符合中心的Brinkman-Rice图片的相关金属附近的莫特绝缘状态的原则，并排除了替代方案中的载流子浓度在金属-绝缘体过渡连续消失。
One early triumph of quantum physics is the explanation why some materials are metallic whereas others are insulating. While a treatment based on single electron states is correct for most materials this approach can fail spectacularly, when the electrostatic repulsion between electrons causes strong correlations. Not only can these favor new and subtle forms of matter, such as magnetism or superconductivity, they can even cause the electrons in a half-filled energy band to lock into position, producing a correlated, or Mott insulator. The transition into the Mott insulating state raises important fundamental questions. Foremost among these is the fate of the electronic Fermi surface and the associated charge carrier mass, as the Mott transition is approached. We report the first direct observation of the Fermi surface on the metallic side of a Mott insulating transition by high pressure quantum oscillatory measurements in NiS2. Our results point at a large Fermi surface consistent with Luttinger’s theorem and a strongly enhanced quasiparticle effective mass. These two findings are in line with central tenets of the Brinkman-Rice picture of the correlated metal near the Mott insulating state and rule out alternative scenarios in which the carrier concentration vanishes continuously at the metal-insulator transition.