Department of Physics and Center for Advanced Nanoscience, University of California, San Diego, La Jolla, California 92093, USA.
Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, California 93106, USA.
Phys Rev Lett. 2019 Feb 8;122(5):057601. doi: 10.1103/PhysRevLett.122.057601.
The interdependences of different phase transitions in Mott materials are fundamental to the understanding of the mechanisms behind them. One of the most important relations is between the ubiquitous structural and electronic transitions. Using IR spectroscopy, optical reflectivity, and x-ray diffraction, we show that the metal-insulator transition is coupled to the structural phase transition in V_{2}O_{3} films. This coupling persists even in films with widely varying transition temperatures and strains. Our findings are in contrast to recent experimental findings and theoretical predictions. Using V_{2}O_{3} as a model system, we discuss the pitfalls in measurements of the electronic and structural states of Mott materials in general, calling for a critical examination of previous work in this field. Our findings also have important implications for the performance of Mott materials in next-generation neuromorphic computing technology.
不同相变之间的相互依存关系是理解其背后机制的基础。最重要的关系之一是普遍存在的结构和电子转变之间的关系。我们使用红外光谱、光学反射率和 X 射线衍射表明,V_{2}O_{3} 薄膜中的金属-绝缘体转变与结构相转变相关联。这种耦合在具有广泛变化的转变温度和应变的薄膜中仍然存在。我们的发现与最近的实验结果和理论预测相矛盾。我们使用 V_{2}O_{3} 作为模型系统,讨论了一般情况下测量莫特材料的电子和结构状态的测量中的陷阱,并呼吁对该领域的先前工作进行批判性审查。我们的发现对莫特材料在下一代神经形态计算技术中的性能也具有重要意义。