Nonadiabatic Transport in Quantum Devices

量子器件中的非绝热传输

• 批准号: 1206784
• 负责人: Andrei Kogan
• 金额: $ 34.8万
• 依托单位: University of Cincinnati Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1206784&HistoricalAwards=false
• 关键词: Nonadiabatic; Transport; Quantum; Devices

****Technical Abstract****This award supports experiments which will probe dynamics of strongly interacting electronic states in nanostructures with the goal of identifying characteristic time scales that separate adiabatic and non-adiabatic regimes, and improving our understanding of non-adiabatic transport in such systems. Using Kondo-correlated states in single-electron transistors as the model, we will characterize transport through the device by measurements of time-averaged current and by a direct measurement of the frequency-dependent SET impedance, a complementary technique which is expected to provide a direct link between experiments and theory. Dynamic aspects of transport in quantum point contacts will be investigated, which will help further understand the role of spin correlation in this fundamental mesoscopic system. The work will complement existing studies of correlated dynamics in bulk materials and will benefit researchers pursuing coherent control of elementary quantum states and those interested in general aspects of quantum dynamics on the nanoscale. The proposed project will integrate research and education goals by supporting the training of a graduate student and undergraduates in modern science and technology, developing teaching experiments for a new course on modern experimental methods and the "physics of everyday life" online course, and offering a summer research camp for a physics teacher and several students on experimental projects related to the main program.****Non-Technical Abstract****Quantum mechanics describes behavior of small building blocks of matter, such as electrons in conductors. Understanding quantum behavior on the most basic scale which involves but a few electrons is widely believed to lead to an improved ability to synthesize materials with finely tailored properties and to advances in developing a fundamentally novel class of electronic devices. One of the challenges is to find accurate methods for predicting behavior of a quantum system that strongly interacts with its environment. This project will focus on the quantum mechanics of a single electronic spin embedded in a conductor, known as Kondo state, and investigate how the state responds to a time-dependent perturbation. The combination of strong interactions with the environment and presence of time-dependent signals is to occur in any solid-state quantum electronic device, and insufficient data are presently available in such a regime for testing theoretical models. One of the questions is how the response of the quantum system with strong interactions changes with the frequency of the applied signal. This project will identify relevant characteristic frequencies and examine the predicted connection between those and the strength of the interaction with the environment, and generate data in the "fast" regimes where novel theories are being developed. The work contributes to the training of skilled technical workforce and contains an integrated education plan to develop a course on modern experimental methods, offer a summer research camp to a physics teacher and several students on experimental projects related to the main program, and construct demonstrations that convey complicated physics topics in a clear visual form to be used in an online "physics of everyday life" course for non-science majors.

* 技术摘要 * 该奖项支持将探测纳米结构中强相互作用电子态的动力学的实验，其目标是确定区分绝热和非绝热状态的特征时间尺度，并提高我们对此类系统中非绝热传输的理解。 使用近藤相关的单电子晶体管作为模型的状态，我们将通过测量时间平均电流和直接测量的频率相关的SET阻抗，一个互补的技术，预计将提供一个直接的实验和理论之间的联系，通过设备的传输特性。量子点接触中的输运动力学方面将被研究，这将有助于进一步理解自旋相关在这一基本介观系统中的作用。这项工作将补充现有的相关动力学在散装材料的研究，并将有利于研究人员追求基本量子态的相干控制和那些感兴趣的一般方面的量子动力学在纳米尺度上。该项目将通过支持现代科学和技术的研究生和本科生的培训，为现代实验方法的新课程和“日常生活的物理学”在线课程开发教学实验，并为物理教师和与主项目相关的实验项目的几名学生提供暑期研究营，从而整合研究和教育目标。非技术摘要 * 量子力学描述了物质的小组成部分的行为，例如导体中的电子。人们普遍认为，在最基本的尺度上理解量子行为（只涉及几个电子），可以提高合成具有精细定制特性的材料的能力，并在开发一种全新的电子器件方面取得进展。 挑战之一是找到准确的方法来预测与环境强烈相互作用的量子系统的行为。该项目将专注于嵌入导体中的单个电子自旋的量子力学，称为Kondo状态，并研究该状态如何响应时间依赖性扰动。与环境的强相互作用和随时间变化的信号的存在的组合将发生在任何固态量子电子器件中，并且目前在这种制度中没有足够的数据来测试理论模型。其中一个问题是具有强相互作用的量子系统的响应如何随所施加信号的频率而变化。该项目将确定相关的特征频率，并研究这些频率之间的预测联系以及与环境相互作用的强度，并在正在开发新理论的“快速”区域生成数据。这项工作有助于培训熟练的技术劳动力，并包含一个综合教育计划，以开发现代实验方法课程，为物理教师和与主要计划有关的实验项目的几名学生提供暑期研究营，并构建演示，以清晰的视觉形式传达复杂的物理主题，用于在线“日常生活物理学”课程，理科专业