NER: High-Bandwidth Scanning DC SQUID Susceptometer for Characterization of Nanomagnetic Structures and Phenomena

NER：用于表征纳米磁性结构和现象的高带宽扫描直流 SQUID 感受器

基本信息

批准号：
0210877
负责人：
Martin Huber
金额：
$ 9.99万
依托单位：
University of Colorado at Denver-Downtown Campus
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2002
资助国家：
美国
起止时间：
2002-08-01 至 2004-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0210877&HistoricalAwards=false
关键词：
NER Bandwidth Scanning DC SQUID

项目摘要

0210877HuberNanomagnetic devices for applications such as quantum computing and high-capacity memory cannot be developed without faster, more sensitive characterization tools to directly probe phenomena and material structures at the nanoscale. The objective of the proposed work is to advance the capability of a non-invasive, high-sensitivity technique-scanning superconducting quantum interference device (SQUID) susceptometry for the dynamic characterization of nanomagnetic systems and phenomena.The principal investigator will achieve this objective through two innovations. First, spin sensitivity will be improved from the current state of the art, a few thousand electron spins per Hz1/2, to a few tens of spins per Hz1/2. This improvement will be accomplished by reduction of pickup loop dimensions in a combined optical and electron-beam lithography process and by utilizing an ultra-low-noise dc SQUID process. Second, bandwidth will be increased from the current state of the art, tens of kHz, to tens of MHz by the use of dc SQUID series array amplifiers as preamplifiers for the dc SQUID susceptometer.The devices will be characterized for flux sensitivity and bandwidth at 4 K and 20 mK. The devices will have many applications at 4 K, although operation at 20 mK will be essential for the study of quantum decoherence mechanisms in electronic systems. Undergraduates, working with graduate students in the collaborator's laboratory, will characterize the spin sensitivity of the devices and their performance under realisticscanning conditions by imaging individual cobalt nanomagnetic spheres of controlled diameters ranging from 3 nm to 10 nm and magnetic moments ranging from tens to tens of thousands of electron spins. Further, one SQUID susceptometer will be used to image a second, identical device to quantitatively characterize the noise generated by the devices.The scientific emphasis of this project is to produce sensors that will have applications in the area of nanoscale structures, novel phenomena, and quantum control and to use these sensors image both static and dynamic properties of individual cobalt nanomagnets. Integration of a high-sensitivity, high-bandwidth SQUID susceptometer into a scanning platform will significantly increase the number and kind of systems that can be studied, decrease turn-around time, and increase the number of samples that can be studied in ansingle experiment. Thus, the successful realization of this project will contribute to advances in nanoscale devices and system architecture. An added benefit of this project will be the educational benefits at both CU-Denver (PI's institution) and Stanford University (collaborator's institution) resulting from the collaboration between CU-Denver undergraduate students and Stanford graduate students.

0210877Huber 如果没有更快、更灵敏的表征工具来直接探测纳米尺度的现象和材料结构，就无法开发用于量子计算和大容量存储器等应用的纳米磁性器件。拟议工作的目标是提高非侵入性、高灵敏度技术扫描超导量子干涉装置（SQUID）电感受器的能力，用于纳米磁性系统和现象的动态表征。主要研究人员将通过两个方面来实现这一目标创新。首先，自旋灵敏度将从目前的技术水平（每 Hz1/2 几千个电子自旋）提高到每 Hz1/2 几十个电子自旋。这一改进将通过减少光学和电子束光刻组合工艺中的拾取环尺寸以及利用超低噪声直流 SQUID 工艺来实现。其次，通过使用 dc SQUID 系列阵列放大器作为 dc SQUID 感受器的前置放大器，带宽将从当前最先进的数十 kHz 增加到数十 MHz。这些器件的通量灵敏度和带宽将在4 K 和 20 mK。尽管在 20 mK 下运行对于研究电子系统中的量子退相干机制至关重要，但这些器件在 4 K 下将有许多应用。本科生将与合作者实验室的研究生合作，通过对受控直径范围为 3 nm 至 10 nm、磁矩范围为数十至数十的单个钴纳米磁球进行成像，来表征器件的自旋灵敏度及其在真实扫描条件下的性能。数千个电子自旋。此外，一个 SQUID 感受器将用于对第二个相同的设备进行成像，以定量表征设备产生的噪声。该项目的科学重点是生产将在纳米级结构、新现象和量子控制并使用这些传感器对单个钴纳米磁体的静态和动态特性进行成像。将高灵敏度、高带宽 SQUID 感受计集成到扫描平台中将显着增加可研究系统的数量和种类，减少周转时间，并增加单次实验中可研究的样品数量。因此，该项目的成功实现将有助于纳米级器件和系统架构的进步。该项目的另一个好处是，通过 CU-丹佛分校本科生和斯坦福大学研究生之间的合作，可以为 CU-丹佛分校（PI 机构）和斯坦福大学（合作者机构）带来教育效益。