EAGER: Creation and Manipulation of Quantum States in Oxide Nanostructures with a Low-Temperature Atomic-Force Microscope

本研究项目旨在了解一种新发现的制造尺寸接近原子尺度的电路的方法背后的基本工作原理。目前的计算机技术是以硅晶体管为基础的，而硅晶体管的尺寸正越来越小。氧化物纳米电子学为制造信息技术所需的晶体管和其他电路元件提供了一种新方法，但许多基本特性仍未得到很好的理解。发展这种理解的一种方法是使用一种叫做原子力显微镜的技术，在这种技术中，在表面上扫描一个小针状探针来测量形状，并通过对探针施加电压来改变其性质。该研究项目将利用这种仪器的扩展功能，允许在比以前可能的低得多的温度下测量其性质。这种控制将有助于揭示纳米级晶体管和其他器件写入和擦除的一些基本机制。该项目将为参与该项目的研究生提供形成性的经验。低温图像很可能创造出这些纳米结构的吸引人的视觉表现，这些图像将吸引那些年轻、易受影响的学生选择他们未来的学术轨迹。技术细节：PI发明了一种在两个绝缘体（LaAlO3和SrTiO3）之间的界面上书写和修改导电纳米结构的新方法。该项目将扩展真空原子力显微镜（AFM）的工作范围，使氧化物纳米结构可以在通过导电AFM尖端探测时冷却到4 K。在低温下，供体部位的载流子的热活化被抑制，揭示了AFM写入过程产生的潜在电位。尖端将充当一个局部门，使纳米结构能够在局部和原位进行探测，并以高空间分辨率绘制潜在轮廓。扩展的温度范围（该仪器目前的工作温度仅为130k）将允许对器件结构进行实时反馈，以便在进行输运测量的温度下定义奇异量子态。

NON-TECHNICAL DESCRIPTIONThis research project seeks to understand the basic operating principle behind a newly discovered method for fabricating circuits whose size approaches atomic-scale dimensions. Current computer technology is based on silicon transistors which are getting close to their smallest possible size. Oxide nanoelectronics offers a new way to create transistors and other circuit elements that are required for information technology, but many basic properties are still not well understood. One way of developing such an understanding is to use a technique called atomic force microscopy, in which a small needle-like probe is scanned over a surface to measure the shape as well as alter the properties by using applied voltages to the probe. This research project will use an extension of the capabilities of such an instrument to allow the properties to be measured at much lower temperatures than was previously possible. Such control will help to uncover some of the basic mechanisms for writing and erasing nanoscale transistors and other devices. The project will provide formative experiences for the graduate student involved in the project. The low-temperature images are likely to create appealing visual representations of these nanostructures, ones that will appeal to young, impressionable students choosing their future academic trajectories.TECHNICAL DETAILSA novel method for writing and modifying conducting nanostructures at the interface between two insulators (LaAlO3 and SrTiO3) has been invented by the PI. This project will extend the operating range of a vacuum atomic force microscope (AFM) so that oxide nanostructures can be cooled to 4 K while being probed by a conducting AFM tip. At low temperatures, thermal activation of carriers from donor site is suppressed, revealing the underlying potential produced by the AFM writing process. The tip will act like a local gate, enabling the nanostructure to be probed locally and in situ, and for the potential profile to be mapping with high spatial resolution. The extended temperature range (the instrument currently operates only down to 130 K) will allow feedback on the device structure in real time so that exotic quantum states can be defined at temperatures where transport measurements are made.