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

• 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

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.

021087775HUBERNANANOMAGNOMAMAGNETIC设备，例如量子计算和高容量记忆，如果没有更快，更敏感的表征工具，以直接探测纳米级的现象和材料结构。拟议工作的目的是提高非侵入性，高敏性技术 - 扫描超导量子干扰装置（Squid）苏联的能力，以实现纳米磁系统和现象的动态表征。主要研究者将通过两项创新实现这一目标。首先，自旋灵敏度将从目前的技术状态（每Hz1/2的几千次电子旋转）提高到每Hz1/2的几十旋转。这种改进将通过在组合的光学和电子束光刻过程中以及使用超低噪声DC鱿鱼过程中降低拾取环尺寸来实现。其次，通过使用DC Squid系列阵列放大器作为DC Squid uSiptermeter的前置放大器，将增加带宽，从数十个KHz的当前状态，即KHz的数十个MHz。 这些设备将在4 K处具有许多应用，尽管在20 MK下的操作对于研究电子系统中的量子反应机制至关重要。 与研究生在合作者实验室合作的本科生将通过对可控直径的单个钴纳米磁球体进行成像，从3 nm到10 nm到10 nm，磁性力矩的旋转敏感性及其在现实降生条件下的旋转敏感性，范围从数十六到数以千计的电子旋转。此外，一个鱿鱼感应仪将用于对第二个相同的设备进行成像，以定量地表征设备产生的噪声。该项目的科学强调是生成传感器，这些传感器将在纳米级结构，新型现象和量子控制和使用这些传感器的静态和动态属性的静态和动态属性中具有应用。 将高敏性，高带宽鱿鱼启示仪集成到扫描平台中将显着增加可以研究的系统的数量和类型，减少转机时间，并增加在Ansingle实验中可以研究的样品数量。因此，该项目的成功实现将有助于纳米级设备和系统体系结构的进步。该项目的额外好处将是Cu-denver（PI的机构）和斯坦福大学（合作者机构）的教育益处，这是由于Cu-denver本科生与斯坦福大学的研究生之间的合作。