CAREER: Electron-phonon processes in gate-defined silicon quantum dots: measurement, control, and applications.

职业：门定义硅量子点中的电子声子过程：测量、控制和应用。

• 批准号: 2046428
• 负责人: Meenakshi Singh
• 金额: $ 68.56万
• 依托单位: Colorado School of Mines
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2046428&HistoricalAwards=false
• 关键词: CAREER; Electron; phonon; processes; gate

Non-technical abstract: Acting like electrically controllable ‘artificial atoms’, quantum dots are a useful system to study a wide range of condensed matter physics phenomena ranging from bond formation and magnetism to the fundamentals of quantum information. In this project, the research team will study the ubiquitous coupling between electrons and phonons. Of particular interest is the impact of the phonons on the spin of the electrons. Control over the phonon-spin interaction, achieved here via nano-structuring and applied strain, has crucial implications for a number of applications, such as quantum computing. In the course of this project, a new generation of undergraduate and graduate students are being trained with expertise in nanoscale fabrication, cryogenics, and microwave measurements. These skills are relevant to the nationwide calls for a quantum workforce. The research efforts are being integrated with the Microelectronics Processing course at Mines via development of illustrative quantum experiments. Finally, modules are being developed to be incorporated into outreach efforts to middle school children in the Rocky Mountain Camp for Dyslexic Children.Technical abstract: Electron-phonon coupling is ubiquitous in Condensed Matter systems. It plays a pivotal role in relaxation and decoherence (in case of multiple spins) of electronic spin states and is predicted to mediate many-body phenomena. An immense body of research on tailoring it in fields as varied as superconductivity and thermoelectrics exists. Insight from these fields has never been applied to experiments in few-spin systems. This is a new and impactful opportunity, since few-spin systems are the fundamental prototype for rationalizing spin dynamics in more complex systems, important for quantum information applications. This project bridges the gap via an experimental effort focused on control and measurement of electron-phonon processes in silicon gate-defined quantum dots. The phonon bath is engineered through nano-structuring and spin-orbit coupling is controlled via applied strain to investigate the theoretically predicted ‘protected’ states. Measurements of spin relaxation and decoherence time are performed. Controlling the coupling of spins to the phonon bath has profound implications. First, it can be used for the design of ‘hot’ qubits and spintronic devices. Second, it leads to an examination of hitherto untested theoretical predictions. Third, the novel protocols developed in the project for sensing nanoscale electron-phonon thermalization are foundational for future quantum thermodynamics studies on the quantum dot platform. Finally, this is a pioneering effort to apply insight from the vast field of nano-phononics to spin qubits and paves the way for future integration of the fields.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术摘要：量子点就像电控“人造原子”一样，是一个有用的系统，可以研究从键形成和磁性到量子信息基础知识的各种凝聚态物理现象。将研究电子和声子之间普遍存在的耦合，特别令人感兴趣的是声子对电子自旋的影响，通过此处实现。纳米结构和应用应变，对量子计算等许多应用具有至关重要的影响。在该项目过程中，新一代本科生和研究生正在接受纳米级制造、低温学和微波测量方面的专业知识培训。这些技能与全国范围内对量子劳动力的呼吁相关，这些研究工作正在通过开发说明性量子实验与矿山的微电子处理课程相结合。最后，正在开发模块以纳入针对中学生的推广工作。在落基山诵读困难儿童营。技术摘要：电子声子耦合在凝聚态物质系统中普遍存在，它在电子自旋态的弛豫和退相干（在多重自旋的情况下）中发挥着关键作用，并且预计会介导多体现象。在超导和热电等各种领域进行的大量研究从未应用于少自旋系统的实验，这是一个新的、有影响力的机会。由于少自旋系统是在更复杂的系统中合理化自旋动力学的基本原型，这对于量子信息应用非常重要，因此该项目通过专注于控制和测量硅门定义的量子点中的电子声子过程的实验工作弥补了这一差距。声子浴是通过纳米结构设计的，并通过施加的应变来控制自旋轨道耦合，以研究理论上预测的“受保护”状态，并进行自旋弛豫和退相干时间的测量。声子浴具有深远的意义，首先，它可以用于“热门”量子位和自旋电子器件的设计，其次，它导致了对迄今为止未经检验的理论预测的检验，第三，该项目中开发了用于传感纳米级电子的新颖协议。 -声子热化是未来量子点平台上的量子热力学研究的基础。最后，这是一项开创性的努力，将纳米声子学的广阔领域的见解应用于旋转量子位，并为量子位的发展铺平了道路。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。