MRI-R2: Development of a Low Temperature Single Spin Tunneling Force Microscope

0959328威廉斯大学关于UtahMRI：低温单自旋隧道力显微镜的发展技术摘要：该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。扫描探针显微镜的最新进展使人们有可能在原子尺度的空间分辨率的电介质表面的个别电子陷阱状态的图像。在该方法中，单个电子被诱导以在扫描探针尖端和表面处的电子状态之间隧穿。每个单独的电子隧穿事件都是通过静电力来检测的。该项目旨在将这一令人兴奋的新能力扩展到单电子自旋的检测和操纵。将研制一种液氦温度单自旋调谐力显微镜，能够进行单自旋电子自旋共振（ESR）测量和单自旋操纵。该仪器将包括一个低温原子力显微镜，修改为力检测自旋相关的单电子隧穿事件与ESR激发。该仪器代表了一种全新的方法，原子尺度的单自旋检测。与之前基于弱磁力检测的方法不同，它基于自旋选择规则的利用。该仪器将使化学/物理识别（g因子，能量，波函数成像）的个别顺磁状态，如点缺陷中发现的电介质和半导体材料，与原子尺度的空间分辨率。它还将提供一种研究原子尺度磁场和自旋弛豫过程的手段，并将开辟一种读出与相邻电子自旋超精细耦合的单个核自旋的方法。该项目将培训本科生和研究生（重点是代表性不足的群体）在最先进的原子尺度测量技术，并开辟了新的合作与研究小组内外的犹他州大学。外行摘要：这个奖项是根据2009年美国复苏和再投资法案（公法111-5）资助。自旋是电子和某些原子核的基本属性，这使得它们像微小的条形磁铁一样。允许观察自旋的技术在过去产生了深远的影响。最突出的例子是基于磁共振，它被用于医学诊断和化学和材料科学的分析方法。这些技术中的大多数检测数十亿个自旋。以前在非常有选择性的自旋系统上进行的一些实验已经证明了单自旋检测。然而，其中大多数都不能很好地解决自旋的空间位置，而其他人则需要极低的温度。拟议的项目旨在开发一种新的显微镜，能够在一定温度范围内以原子尺度的精度检测单个电子自旋。这种仪器被称为单自旋隧道力显微镜。它基于量子力学隧道效应，这种现象允许被困在一个区域的电子穿过一个不可穿透的屏障，并在另一边重新出现。单电子隧穿现象已经用力显微镜观察到。电子自旋可以影响隧穿。在所提出的仪器中，使用自旋相关隧穿原理检测自旋。所提出的显微镜的发展可能会导致许多研究领域的巨大进步。在许多材料和分子系统中观察单个自旋的能力可能会导致未来自旋电子器件的突破。它还可以为量子计算机的发展做出重大贡献，并有助于理解影响传统电子材料和器件的原子尺度缺陷。对这些缺陷自旋的研究可以深入了解太阳能电池、半导体照明设备、显示器和计算机应用的改进策略。

0959328WilliamsU. of UtahMRI: Development of a Low Temperature Single Spin Tunneling Force MicroscopeTechnical Summary: This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). A recent advance in Scanning Probe Microscopy has made it possible to image individual electron trap states in dielectric surfaces with atomic scale spatial resolution. In this method, a single electron is induced to tunnel between a scanning probe tip and an electronic state at the surface. Each individual electron tunneling event is detected by electrostatic force. This project aims to expand this exciting new capability to the detection and manipulation of single electron spins. A liquid helium temperature Single Spin Tunneling Force Microscope will be developed, capable of performing single spin Electron Spin Resonance (ESR) measurements and single spin manipulation. The instrument will consist of a low temperature Atomic Force Microscope, modified for force detection of spin-dependent single electron tunneling events with ESR excitation. The proposed instrument represents an entirely new approach to atomic scale single spin detection. It is based on the utilization of spin-selection rules, in contrast to previous approaches based on the detection of weak magnetic force detection. The instrument will enable chemical/physical identification (g-factor, energy, wavefunction imaging) of individual paramagnetic states, such as point defects found in dielectric and semiconductor materials, with atomic scale spatial resolution. It will also provide a means to study atomic scale magnetic fields and spin relaxation processes and will open a way to read out individual nuclear spins that are hyperfine coupled to adjacent electron spins. The project will train undergraduate and graduate students (emphasis on underrepresented groups) in state of the art atomic scale measurement techniques, and open up new collaborations with research groups within and outside the University of Utah.Layman Summary: This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Spin is a fundamental property of electrons and some nuclei, which causes them to act like tiny bar magnets. Techniques allowing the observation of spins have had a profound impact in the past. The most prominent examples are based upon magnetic resonance, which is employed in medical diagnostics and analytical methods for chemistry and materials science. Most of these techniques detect many billions of spins. A few previous experiments conducted on very selective spin systems have demonstrated single spin detection. Most of these however could not resolve the spatial location of the spins very well, while others required extremely low temperatures. The proposed project aims to develop a new microscope which is able to detect individual electron spins with atomic scale precision over a range of temperatures. This instrument is called the Single Spin Tunneling Force Microscope. It is based on the quantum mechanical tunneling effect, a phenomena that allows electrons trapped in one region to traverse an impenetrable barrier and reappear on the other side. Tunneling of single electrons has already been observed with force microscopy. Tunneling can be influenced by electron spin. In the proposed instrument, spins are detected using the principle of spin dependent tunneling. The development of the proposed microscope could lead to dramatic progress in many research fields. The ability to observe individual spins in many materials and molecular systems could lead to breakthroughs for future spintronic devices. It could also significantly contribute to the development of quantum computers and help to understand atomic scale defects which influence conventional electronic materials and devices. The study of these defect spins can lead to insights into strategies for improvements in solar cells, semiconductor lighting devices, displays and computer applications.