论文标题
钙钛矿氧化物中电荷载体的电子二极性二分法
Electron-polaron dichotomy of charge carriers in perovskite oxides
论文作者
论文摘要
许多过渡金属氧化物（TMO）是莫特绝缘子，这是由于电子之间的强库仑排斥力，并且展示了金属绝缘体过渡（MIT），其机制并不总是完全理解。与大多数TMO不同，CAMNO3中的微小掺杂会诱导金属状态，而没有任何结构转换。因此，该材料是通过麻省理工学院探索带形成的理想平台。在这里，我们使用角度分辨的光发射光谱来可视化电子脱位和夫妇在CAMNO3中的声子。我们展示了费米表面的发展，其中移动电子与较重的载体共存，强烈耦合极性。后者起源于电子相互作用（EPI）的提升。这一发现阐明了EPI在MIT中甚至由纯电子机制引起的MIT中所起的作用。我们发现电荷载体的表诱导的二分法解释了CE掺杂的CAMNO3的运输响应，并提出了从TMOS来设计量子问题的策略。
Many transition metal oxides (TMOs) are Mott insulators due to strong Coulomb repulsion between electrons, and exhibit metal-insulator transitions (MITs) whose mechanisms are not always fully understood. Unlike most TMOs, minute doping in CaMnO3 induces a metallic state without any structural transformations. This material is thus an ideal platform to explore band formation through the MIT. Here, we use angle-resolved photoemission spectroscopy to visualize how electrons delocalize and couple to phonons in CaMnO3. We show the development of a Fermi surface where mobile electrons coexist with heavier carriers, strongly coupled polarons. The latter originate from a boost of the electron-phonon interaction (EPI). This finding brings to light the role that the EPI can play in MITs even caused by purely electronic mechanisms. Our discovery of the EPI-induced dichotomy of the charge carriers explains the transport response of Ce-doped CaMnO3 and suggests strategies to engineer quantum matter from TMOs.
