论文标题
Mott物理的细分$ _2 $表面
The Breakdown of Mott Physics at VO$_2$ Surfaces
论文作者
论文摘要
已知过渡金属氧化物，例如二氧化钒（Vo $ _2 $），二氧化氮氧化物（NBO $ _2 $）和钛sesquioxide（Ti $ _2 $ o $ $ _3 $），可以通过与结构过渡的结构过渡进行温度依赖的金属仪器过渡（MIT）进行组合过渡。然而，通常不讨论通过表面终止如何破坏晶体对称性会影响复杂的麻省理学物理学。使用基于同步加速器的X射线光谱，低能电子衍射（LEED），低能电子显微镜（LEEM），透射电子显微镜（TEM）和其他几种实验技术，我们表明，抑制块状结构过渡是一种常见特征，在vo $ _2 $表面上是一种常见的特征。我们的密度功能理论（DFT）的计算进一步表明，这是由于稳定表面所需的固有重建，这会使电子结构偏离散装d $^1 $配置。我们的发现不仅在表征其他“类似Mott”的MIT的情况下，而且对于此类材料的任何潜在设备应用，都具有更广泛的影响。
Transition metal oxides such as vanadium dioxide (VO$_2$), niobium dioxide (NbO$_2$), and titanium sesquioxide (Ti$_2$O$_3$) are known to undergo a temperature-dependent metal-insulator transition (MIT) in conjunction with a structural transition within their bulk. However, it is not typically discussed how breaking crystal symmetry via surface termination affects the complicated MIT physics. Using synchrotron-based x-ray spectroscopy, low energy electron diffraction (LEED), low energy electron microscopy (LEEM), transmission electron microscopy (TEM), and several other experimental techniques, we show that suppression of the bulk structural transition is a common feature at VO$_2$ surfaces. Our density functional theory (DFT) calculations further suggest that this is due to inherent reconstructions necessary to stabilize the surface, which deviate the electronic structure away from the bulk d$^1$ configuration. Our findings have broader ramifications not only for the characterization of other "Mott-like" MITs, but also for any potential device applications of such materials.
