Metal-insulator transition of the two-band Hubbard model in infinite dimension and its relevance to a strongly correlated electron system: NiS 2-x Se x
Metal-insulator transition of the two-band Hubbard model in infinite dimension and its relevance to a strongly correlated electron system: NiS 2-x Se x
复制标题
无限维双能哈伯德模型的金属-绝缘体转变及其与强相关电子系统的相关性：NiS 2-x Se x
DOI：
10.1103/physrevb.57.3829
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发表时间：
1998
影响因子：
3.7
通讯作者：
S. Doniach
中科院分区：
文献类型：
--
作者：
H. Watanabe;S. Doniach
利用动力学平均场理论研究了强关联双带Hubbard模型的金属-绝缘体相变。我们发现，莫特转变出现在半填充，甚至在$T=0$相比，单带哈伯德模型。这种转变的特征是在费米能级附近出现了一个“近藤状”峰。通过对单粒子绿色函数和关联电子间超交换耦合导致的磁长程有序的研究，我们还发现了金属相和反铁磁相共存的特征.然后，我们建议的相关性，我们的结果的金属-绝缘体转变和最近的角分辨光电发射测量的${\mathrm{NiS}}_{2\ensuremath {-}x}{\mathrm{Se}}_{x}。我们还研究了载流子掺杂的影响，并将我们的研究结果与实验结果进行比较，表明偏离与Se取代相关的化学计量的可能重要性。我们的结果的高温超导性的相关性进行了讨论。
We report a study of metal-insulator transition of a strongly correlated two-band Hubbard model using a dynamical mean-field theory approach. We find that the Mott transition appears at half filling even at $T=0$ in contrast to the one-band Hubbard model. The transition is characterized by the development of a ``Kondo-like'' peak near Fermi level. We also find a signature of the coexistence of metallic and antiferromagnetic phases from the study of the single-particle Green's function and the magnetic long-range order due to the superexchange coupling between the correlated electrons. We then suggest the relevance of our results to the metal-insulator transition and the recent angle-resolved photoemission measurements of ${\mathrm{NiS}}_{2\ensuremath{-}x}{\mathrm{Se}}_{x}.$ We also study the effect of carrier doping and the comparison of our findings with the experimental results suggests the possible importance of departures from stoichiometry associated with the Se substitution. The relevance of our results to high-temperature superconductivity is also discussed.