Dimensional-crossover-driven metal-insulator transition in SrVO3 ultrathin films.
Dimensional-crossover-driven metal-insulator transition in SrVO3 ultrathin films.
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DOI：
10.1103/physrevlett.104.147601
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发表时间：
2010-04
影响因子：
8.6
通讯作者：
K. Yoshimatsu;T. Okabe;H. Kumigashira;H. Kumigashira;S. Okamoto;S. Aizaki;A. Fujimori;M. Oshima
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文献类型：
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作者：
K. Yoshimatsu;T. Okabe;H. Kumigashira;H. Kumigashira;S. Okamoto;S. Aizaki;A. Fujimori;M. Oshima
我们利用原位光电子能谱研究了数控SrVO(3)超薄膜在金属-绝缘体转变(MIT)过程中通过薄膜厚度发生的电子结构变化。随着膜厚度的减小，通过从相干部分到非相干部分的光谱权重转移，在E(F)处形成赝能隙。赝能隙最终演变成代表 SrVO(3) 超薄膜中 MIT 的能隙。观察到的光谱行为通过层动态平均场理论计算再现，这表明观察到的 MIT 是由维度交叉导致的带宽减少引起的。
We have investigated the changes occurring in the electronic structure of digitally controlled SrVO(3) ultrathin films across the metal-insulator transition (MIT) by the film thickness using in situ photoemission spectroscopy. With decreasing film thickness, a pseudogap is formed at E(F) through spectral weight transfer from the coherent part to the incoherent part. The pseudogap finally evolves into an energy gap that is indicative of the MIT in a SrVO(3) ultrathin film. The observed spectral behavior is reproduced by layer dynamical-mean-field-theory calculations, and it indicates that the observed MIT is caused by the reduction in the bandwidth due to the dimensional crossover.