All-Optical Quantum Computing with Femtosecond Coherent Control of Excitons in Semiconductor Quantum Dots

半导体量子点中激子的飞秒相干控制的全光量子计算

• 批准号: 0605854
• 负责人: David Snoke
• 金额: --
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0605854&HistoricalAwards=false
• 关键词: Optical; Quantum; Computing; Femtosecond; Coherent

*****NON-TECHNICAL ABSTRACT*****The power of quantum mechanics will allow quantum computers, once realized, to perform tasks that are well beyond the power of classical computers. An example of such a task is the breaking of strong encryption, an important topic for national security. Quantum information, however, is much more volatile and difficult to handle than classical information, and approaches for quantum computation demonstrated so far can handle a few quantum bits at best. This individual investigator award supports an experimental research program to demonstrate quantum gating in semiconductor quantum dots of nanometer size. Quantum dots are made from layers of semiconductors and behave like artificial atoms whose quantum states can be controlled by sequences of very fast laser pulses. The project will investigate the basic elements for quantum circuits. The experiments will concentrate on optimum control and measurement of the quantum states in quantum dots, the rate of errors from loss of the volatile quantum information (decoherence), the maximum speed with which the dots can process quantum information, and coupling mechanisms between dots necessary for two-bit gates. The research will involve graduate and undergraduate students and therefore have a strong educational component in important fields such as ultrafast optics, nanoscience and quantum engineering.***** TECHNICAL ABSTRACT*****This individual investigator award supports an experimental research program that explores femtosecond coherent quantum control of excitonic states in semiconductor quantum dots as a potential platform for scalable quantum computing. The quantum dots are controlled with multi-color optical pulse sequences derived by Fourier domain pulse shaping of femtosecond laser pulses. The experimental program will investigate strongly confined high-quality single and coupled InGaAs and AlGaAs quantum dots that have nanosecond coherence times, allowing potentially thousands of quantum operations before decoherence occurs. The first part of the project will concentrate on single quantum dots and explore new methods of controlling and measuring their quantum states. The experiments will explore the sources of decoherence during quantum operations, such as excitation-induced polaronic lattice distortion with phonon emission. The second part of the project will concentrate on scalability and aims to demonstrate quantum gating of bits located in separate quantum dots. This project integrates research and education of graduate and undergraduate students, and provides hands-on experience in important fields such as ultrafast optics, nanoscience, and quantum engineering.

* 非技术摘要 * 量子力学的力量将允许量子计算机一旦实现，就可以执行远远超出经典计算机能力的任务。这种任务的一个例子是破解强加密，这是国家安全的一个重要课题。然而，量子信息比经典信息更不稳定，更难以处理，到目前为止，量子计算的方法最多只能处理几个量子比特。这个个人研究奖支持一个实验研究计划，以证明量子门在半导体量子点的纳米尺寸。量子点是由多层半导体制成的，其行为就像人造原子，其量子态可以由非常快的激光脉冲序列控制。该项目将研究量子电路的基本元素。实验将集中在量子点中量子态的最佳控制和测量，易失性量子信息（退相干）丢失的错误率，量子点处理量子信息的最大速度，以及两位门所需的量子点之间的耦合机制。该研究将涉及研究生和本科生，因此在超快光学，纳米科学和量子工程等重要领域具有很强的教育成分。技术摘要 * 该个人研究者奖支持一项实验研究计划，该计划探索半导体量子点中激子态的飞秒相干量子控制，作为可扩展量子计算的潜在平台。利用飞秒激光脉冲的傅里叶域脉冲整形技术，实现了对量子点的多色光脉冲序列控制。该实验计划将研究具有纳秒相干时间的强限制的高质量单个和耦合InGaAs和AlGaAs量子点，允许在退相干发生之前进行数千次量子操作。该项目的第一部分将集中在单量子点上，并探索控制和测量其量子态的新方法。实验将探索量子操作过程中退相干的来源，例如激发诱导的极化子晶格畸变与声子发射。该项目的第二部分将专注于可扩展性，旨在展示位于不同量子点中的比特的量子门控。该项目整合了研究生和本科生的研究和教育，并在超快光学，纳米科学和量子工程等重要领域提供实践经验。