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

非技术描述这项研究项目试图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基于硅晶体管的，这种晶体管正在接近其可能的最小尺寸。氧化物纳米电子学提供了一种新的方法来制造信息技术所需的晶体管和其他电路元件，但许多基本特性仍然没有被很好地理解。发展这种理解的一种方法是使用一种名为原子力显微镜的技术，即在表面上扫描一个针状的小探头，通过对探头施加电压来测量形状和改变特性。这项研究项目将使用这种仪器的扩展功能，使其能够在比以前可能的温度低得多的温度下进行测量。这种控制将有助于揭示写入和擦除纳米级晶体管和其他设备的一些基本机制。该项目将为参与该项目的研究生提供成长经验。低温图像很可能为这些纳米结构创造出吸引人的视觉表现，这些结构将吸引年轻的、易受影响的学生选择他们未来的学术轨迹。技术人员发明了一种在两个绝缘体(LaAlO_3和SrTiO_3)之间的界面写入和修改导电纳米结构的新方法。该项目将扩大真空原子力显微镜(AFM)的工作范围，使氧化物纳米结构可以在被导电AFM针尖探测的同时冷却到4K。在低温下，来自施主位置的载流子的热激活被抑制，揭示了AFM写入过程产生的潜在电势。尖端将起到局部栅极的作用，使纳米结构能够被局部和原位探测，并以高空间分辨率绘制潜在的轮廓。扩展的温度范围(该仪器目前只能工作到130K)将允许实时反馈设备结构，以便可以在进行输运测量的温度下定义奇异的量子态。

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.