Non-universal current flow near the metal-insulator transition in an oxide interface
Eylon Persky, Naor Vardi, Ana Mafalda R. V. L. Monteiro, Thierry C. van Thiel, Hyeok Yoon, Yanwu Xie, Benoît Fauqué, Andrea D. Caviglia, Harold Y. Hwang, Kamran… 展开作者
Eylon Persky, Naor Vardi, Ana Mafalda R. V. L. Monteiro, Thierry C. van Thiel, Hyeok Yoon, Yanwu Xie, Benoît Fauqué, Andrea D. Caviglia, Harold Y. Hwang, Kamran Behnia, Jonathan Ruhman, Beena Kalisky
In systems near phase transitions, macroscopic properties often follow algebraic scaling laws, determined by the dimensionality and the underlying symmetries of the system. The emergence of such universal scaling implies that microscopic details are irrelevant. Here, we locally investigate the scaling properties of the metal-insulator transition at the LaAlO3/SrTiO3 interface. We show that, by changing the dimensionality and the symmetries of the electronic system, coupling between structural and electronic properties prevents the universal behavior near the transition. By imaging the current flow in the system, we reveal that structural domain boundaries modify the filamentary flow close to the transition point, preventing a fractal with the expected universal dimension from forming. Our results offer a generic platform to engineer electronic transitions on the nanoscale.
Diminished Short Channel Effects in Nanoscale Double-Gate Silicon-On-Insulator Metal-Oxide- Semiconductor Field-Effect-Transistors due to Induced Back-Gate Step Potential
Spin absorption at ferromagnetic-metal/platinum-oxide interface
通过测量电流感生铁磁共振，研究了自旋电流在铁磁金属/铂氧化物界面的吸收。自旋吸收由异质结构的磁阻尼来表征。我们表明，磁阻尼的Ni $_{81}$ Fe $_{19}$膜的明显增强，通过附加Pt氧化物上的Ni $_{81}$ Fe $_{19}$膜。通过在Ni $_{81}$ Fe $_{19}$和Pt氧化物层之间插入一层Cu层，阻尼增强消失。这些结果证明了Ni $_{81}$ Fe $_{19}$和Pt氧化物之间的直接接触对诱导相当大的界面自旋轨道耦合的重要作用。此外，Ni $_{81}$ Fe $_{19}$ /Pt-氧化物界面的自旋吸收参数与深入研究的具有强自旋-轨道耦合的异质结构（例如氧化物界面、拓扑绝缘体、具有Rashba自旋-轨道耦合的金属结）的自旋吸收参数相当。这一结果说明了强自旋轨道耦合在铁磁金属/铂氧化物界面，提供了一个重要的信息，定量了解自旋吸收和自旋电荷转换在铁磁金属/金属氧化物界面。
Contact effects on transport in magnetite, an archetypal correlated transition metal oxide
多端测量通常被用来检查强相关的电子材料，如过渡金属氧化物的电子性质，而不受接触效应的影响。相比之下，在这项工作中，我们调查的界面性质的Fe $_3$ O $_4$与不同的金属，与接触效应提供了一个窗口的相关氧化物中的物理工作。接触电阻通过四端电气测量作为电源电压和温度的函数来确定。接触电阻随电极金属$ϕ(M)$、$M=$ Cu、Au和Pt的功函数而系统地变化，功函数越高，接触电阻越低。这种趋势和接触电阻与Fe $_3$ O $_4$电阻率成正比的观察结果与将氧化物建模为具有跳跃传输的有效$p$型半导体一致。在偏置驱动的绝缘体-金属转变处的接触电阻值的跳跃具有与$ϕ$（$M$）类似的趋势，与通过电场的电荷间隙闭合的转变机制一致。
