Single-Electron Mediated Charge, Spin and Lattice Interactions in Oxide Nanostructures

氧化物纳米结构中单电子介导的电荷、自旋和晶格相互作用

• 批准号: 1104191
• 负责人: Jeremy Levy
• 金额: $ 71.11万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1104191&HistoricalAwards=false
• 关键词: Single; Electron; Mediated; Charge; Spin

NON-TECHNICAL DESCRIPTIONThis research project will help provide physical understanding of a new oxide-based system capable of information storage and sensing at scales approaching the distance between atoms. Using a technique analogous to the perennial toy "etch-a-sketch", devices that operate with single electrons are being created. These devices store information at very high densities, and they are also predicted to be ultrasensitive sensors of both force and charge. The combined sensitivity, once understood properly, can be used to develop new types of devices and technologies. Aligned with the research goals are mentoring strategies for helping undergraduates learn advanced (but essential) subjects such as quantum mechanics. Mentoring strategies for underrepresented groups are also being pursued for both undergraduate and graduate students.TECHNICAL DETAILSThis research project will identify and develop novel couplings between electron charge, spin, and nanomechanical degrees of freedom in oxide nanostructures. The research centers on a recently developed ferroelectric sketch-based single-electron transistor ("SketchSET"). Resonant tunneling into the SketchSET is modified by the ferroelectric polarization in SrTiO3, enabling an ultrasensitive electronic readout of the ferroelectric polarization (or strain) state. Initial experiments are further characterizing the SketchSET devices, and helping to define the relationship between writing parameters, charging energies, and tunnel barriers. The two-dimensional confining potential V(x,y) that forms the SketchSET are being mapped using a cryogenic atomic force microscope (AFM). Nanomechanical coupling is also being investigated using the piezoelectric and inverse-piezoelectric effects. Subsequent experiments couple a nanoscale mechanical object (e.g., C60 molecule or nanocrystalline quantum dot) placed atop the SketchSET and investigate coupling to phonon modes through inelastic tunneling experiments. Spintronic effects are being investigated at low temperature and high magnetic fields (50 mK/9T), with the purpose of investigating spin relaxation times and gauging the applicability of these systems for spin-based quantum information platforms. The Kondo regime for SketchSETs are being investigated, with a longer-term goal of creating artificial networks of localized and delocalized spin systems. Graduate students are receiving broad-based training in advanced techniques including sample processing, scanning probe microscopy and low-temperature magneto-transport.

该研究项目将有助于提供对一种新的基于氧化物的系统的物理理解，该系统能够在接近原子之间距离的尺度上进行信息存储和传感。 使用一种类似于常年玩具“蚀刻素描”的技术，用单电子操作的设备正在被创造出来。 这些设备以非常高的密度存储信息，并且它们也被预测为力和电荷的超灵敏传感器。 一旦正确理解了组合的灵敏度，就可以用来开发新型设备和技术。 与研究目标相一致的是指导策略，帮助本科生学习先进的（但必要的）学科，如量子力学。 指导策略为代表性不足的群体也正在追求本科生和研究生。技术专长本研究项目将确定和开发新的耦合之间的电子电荷，自旋和纳米力学自由度的氧化物纳米结构。 该研究集中在最近开发的基于铁电草图的单电子晶体管（“SketchSET”）上。 进入SketchSET的共振隧穿通过SrTiO 3中的铁电极化进行修改，从而实现铁电极化（或应变）状态的超灵敏电子读出。 初步实验进一步表征了SketchSET器件，并帮助定义写入参数、充电能量和隧道势垒之间的关系。 形成SketchSET的二维限制势V（x，y）正在使用低温原子力显微镜（AFM）进行映射。 纳米机械耦合也正在研究使用压电和反压电效应。 随后的实验将纳米级机械物体（例如，C60分子或纳米晶体量子点）放置在SketchSET的顶部，并通过非弹性隧穿实验研究耦合到声子模式。 自旋子效应正在低温和高磁场（50 mK/9 T）下进行研究，目的是研究自旋弛豫时间并衡量这些系统对基于自旋的量子信息平台的适用性。 SketchSET的近藤机制正在研究中，其长期目标是创建局域和离域自旋系统的人工网络。 研究生正在接受基础广泛的先进技术培训，包括样品处理，扫描探针显微镜和低温磁输运。