Distinct nature of orbital-selective Mott phases dominated by low-energy local spin fluctuations
Distinct nature of orbital-selective Mott phases dominated by low-energy local spin fluctuations
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由低能局部自旋涨落主导的轨道选择性莫特相的独特性质
DOI：
10.1103/physrevb.96.235119
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发表时间：
2017
影响因子：
3.7
通讯作者：
Zhang Yu-Zhong
中科院分区：
文献类型：
--
作者：
Song Ze-Yi;Jiang Xiu-Cai;Lin Hai-Qing;Zhang Yu-Zhong
基于双轨道Hubbard模型，在动力学平均场理论下研究了半填充区带宽不同的量子轨道选择性Mott跃迁。我们发现了两个不同的OSM相，它们都显示了巡回电子和局域自旋的共存，这取决于Hund的耦合是完全的还是伊辛型的。纠缠熵有效地决定了OSM跃迁的临界值和性质。我们揭示了在Ising Hund耦合情况下非费米液体OSM相的出现是由于在局域动力学自旋极化率的低频没有局域自旋涨落所证明的Kondo能级的消失。我们认为，当考虑短程反铁磁序时，这种情形也可以用来解释单带Hubbard模型中出现的量子非费米液体。
Quantum orbital selective Mott (OSM) transitions are investigated within dynamical mean-field theory based on a two-orbital Hubbard model with different bandwidth at half filling. We find two distinct OSM phases both showing coexistence of itinerant electrons and localized spins, dependent on whether the Hund's coupling is full or of Ising type. The critical values and the nature of the OSM transitions are efficiently determined by entanglement entropy. We reveal that vanishing of the Kondo energy scale evidenced by absence of local spin fluctuations at low frequency in local dynamical spin susceptibility is responsible for the appearance of non-Fermi-liquid OSM phase in Ising Hund's coupling case. We argue that this scenario can also be applied to account for emergent quantum non-Fermi liquid in one-band Hubbard model when short-range antiferromagnetic order is considered.