Determination of the surface and interface phase shifts in metallic quantum well structures of perovskite oxides
Determination of the surface and interface phase shifts in metallic quantum well structures of perovskite oxides
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DOI：
10.1103/physrevb.88.115308
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发表时间：
2013-09
影响因子：
3.7
通讯作者：
K. Yoshimatsu;E. Sakai;Masaki Kobayashi;K. Horiba;T. Yoshida;A. Fujimori;M. Oshima;H. Kumigashira
中科院分区：
文献类型：
--
作者：
K. Yoshimatsu;E. Sakai;Masaki Kobayashi;K. Horiba;T. Yoshida;A. Fujimori;M. Oshima;H. Kumigashira
我们提出了一种实验方法来分别提取由等结构钙钛矿氧化物组成的金属量子阱结构中驻波的表面和界面相移。‘非对称’真空/SrVO${}_{3}$/SrTiO${}_{3}$和‘’对称‘’SrTiO${}_{3}$/SrVO${}_{3}$/SrTiO${}_3}$QW结构是以外延多层结构的形式制备的。利用这些金属量子阱结构，通过分析角分辨光电子能谱的厚度序列，成功地获得了表面(真空/SrVO{3}$)和界面(SrTiO${}{3}$/SrVO${}{3}$)的相移。两种晶界之间的相移差异表明，在界面处实现了接近理想的量子限制，表明SrTiO4{}{3}$层起到了有效势垒的作用。
We propose an experimental approach to extract separately the surface and interface phase shift of standing waves in metallic quantum well (QW) structures composed of isostructural perovskite oxides. The ``asymmetric'' vacuum/SrVO${}_{3}$/SrTiO${}_{3}$ and ``symmetric'' SrTiO${}_{3}$/SrVO${}_{3}$/SrTiO${}_{3}$ QW structures are fabricated in an epitaxial multilayer form. Using these metallic QW structures, the phase shifts at the surface (vacuum/SrVO${}_{3}$) and interface (SrTiO${}_{3}$/SrVO${}_{3}$) are successfully obtained by analyzing a thickness series of angle-resolved photoemission spectra. The difference of the phase shift between the two boundaries reveals that nearly ideal quantum confinement is achieved at the interface, indicating that a SrTiO${}_{3}$ layer acts as a useful potential barrier.