Fermi condensation near van Hove singularities within the Hubbard model on the triangular lattice.
Fermi condensation near van Hove singularities within the Hubbard model on the triangular lattice.
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DOI：
10.1103/physrevlett.112.070403
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发表时间：
2013-08
影响因子：
8.6
通讯作者：
D. Yudin;D. Hirschmeier;H. Hafermann;O. Eriksson;A. Lichtenstein;M. Katsnelson
中科院分区：
文献类型：
--
作者：
D. Yudin;D. Hirschmeier;H. Hafermann;O. Eriksson;A. Lichtenstein;M. Katsnelson
费米面与货车霍韦奇点的接近极大地增强了相互作用效应，并导致了本质上新的物理学。在这项工作中，我们解决了形成的平面带（“费米凝聚”）内的哈伯德模型的三角形晶格，并提供了详细的分析，从分析和数值的角度来看。为了描述这种效应，我们考虑弱耦合和强耦合的方法，即重整化群和对偶费米子方法。它示出的带平坦化的相关性驱动，并且是非常明显的，即使在足够高的温度下，的顺序的0.1-0.2的跳跃参数。因此，可以在光学晶格中用超冷费米子进行实验来探测这种效应。
The proximity of the Fermi surface to van Hove singularities drastically enhances interaction effects and leads to essentially new physics. In this work we address the formation of flat bands ("Fermi condensation") within the Hubbard model on the triangular lattice and provide a detailed analysis from an analytical and numerical perspective. To describe the effect we consider both weak-coupling and strong-coupling approaches, namely the renormalization group and dual fermion methods. It is shown that the band flattening is driven by correlations and is well pronounced even at sufficiently high temperatures, of the order of 0.1-0.2 of the hopping parameter. The effect can therefore be probed in experiments with ultracold fermions in optical lattices.