Tunneling Spectroscopy of Electron-in-a-Box Energy Levels in Metal Nanoparticles

金属纳米颗粒中电子盒能级的隧道光谱

• 批准号: 0071631
• 负责人: Daniel Ralph
• 金额: --
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0071631&HistoricalAwards=false
• 关键词: Tunneling; Spectroscopy; Electron; Box; Energy

This experimental condensed matter physics project deals with nanofabrication techniques that will enable electronic devices that operate by means of physical mechanisms different from existing technology. By incorporating a single metal particle less than 10 nm in diameter into a tunneling device, it becomes possible to manipulate the flow of electrons via individual "electron-in-a-box" energy levels within the particle, and to measure the spectrum of these quantum-mechanical states. This research will study the processes which affect electron transport in this new regime-at the level of single energy levels-for magnetic, superconducting, and normal-metal particles. In addition, the ability to measure the spectrum of quantum levels in a nanoparticle will be used as a tool in investigations of other fundamental questions of nm-scale physics. Topics of primary interest include spin-polarized electron tunneling into single quantum states, the mechanisms of energy and spin relaxation between energy levels, the effects of electronic interactions on the level spectra, the mechanisms of magnetization reversal in nm-scale ferromagnetic particles, and the effects of impurities on quantized energy levels. The research provides exceptional opportunities for graduate students and research associates to be trained in frontier science areas that will prepare them for a range of careers in industry, academe, and government.%%%When a piece of metal is made less than about 10 nanometers in diameter, so that it contains about 10,000 atoms or less, electrons cannot flow through the metal particle with an arbitrary energy- they can flow only with only one of a restricted range of so-called quantized energies. This means that very small electrical devices are entering a new regime, where electrons can be manipulated to flow via individual energy states, in contrast to existing devices where the energy levels are effectively a continuum of states. This experimental condensed matter physics project is aimed at characterizing and understanding all the processes which affect electron flow in this new regime-at the level of single energy levels- for magnetic, superconducting, and normal-metal particles. In addition, the ability to measure the spectrum of electronic levels in a nano-particle will be used as a tool in investigations of other fundamental questions of nanometer-scale physics, such as the behavior of the electron's spin when an electron hops onto a small magnetic particle, the rate at which an electron may relax from a higher-energy to low-energy state within a particle, and the effects of impurities on the quantized levels. The research provides exceptional opportunities for graduate students and research associates to be trained in frontier science areas that will prepare them for a range of careers in industry, academe, and government.***

这个实验凝聚态物理项目涉及纳米纤维技术，将使电子设备通过不同于现有技术的物理机制运行。通过将直径小于10 nm的单个金属颗粒并入隧穿器件中，可以通过颗粒内的单个“电子盒”能级来操纵电子流，并测量这些量子力学状态的光谱。本研究将探讨在单能级水平上，磁性、超导和正常金属粒子在这种新机制下影响电子输运的过程。此外，测量纳米粒子中量子能级光谱的能力将被用作研究纳米尺度物理学其他基本问题的工具。 主要的兴趣包括自旋极化电子隧穿进入单量子态，能级之间的能量和自旋弛豫机制，电子相互作用对能级谱的影响，纳米尺度铁磁粒子的磁化反转机制，以及杂质对量子化能级的影响。这项研究为研究生和研究助理提供了在前沿科学领域接受培训的绝佳机会，这将为他们在工业，工业和政府中的一系列职业生涯做好准备。当一块金属的直径小于10纳米时，它包含大约10，000个原子或更少，电子不能以任意能量流过金属颗粒-它们只能以有限范围内的所谓量子化能量之一流动。这意味着非常小的电子设备正在进入一个新的领域，在这个领域中，电子可以被操纵以通过各个能量状态流动，而现有的设备中的能级实际上是一个连续的状态。这个实验性凝聚态物理项目的目的是表征和理解在这种新制度下（在单能级水平上）影响磁性、超导和正常金属粒子电子流动的所有过程。 此外，测量纳米粒子中电子能级谱的能力将被用作研究纳米尺度物理学其他基本问题的工具，例如当电子跳到小磁性粒子上时电子自旋的行为，电子从高能状态弛豫到低能状态的速率，以及杂质对量子化能级的影响。这项研究为研究生和研究人员提供了在前沿科学领域接受培训的绝佳机会，这将使他们为工业，工业和政府的一系列职业生涯做好准备。