Optical Preparation and Manipulation of Entangled Spin States in Quantum Dot Molecules

量子点分子中纠缠自旋态的光学制备和操纵

• 批准号: 1005525
• 负责人: Eric Stinaff
• 金额: $ 27万
• 依托单位: Ohio University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1005525&HistoricalAwards=false
• 关键词: Optical; Preparation; Manipulation; Entangled; Spin

****NON-TECHNICAL ABSTRACT****An electron possesses a property known as spin, behaving in many ways like a tiny magnet. However, unlike familiar bar magnets, when the electron's spin is measured it points in only one of two directions, sometimes referred to as 'up' or 'down' or like a computer bit "1" or "0". In addition to this binary nature, the spin can also be in a state where it is 'pointing' in both directions 'up' and 'down' at the same time. A set of spins in such a state would contain all possible combinations of a classical set of bits. The capacity for a set of quantum bits to hold such an enormous amount of information would provide an exponential increase in computing power. Therefore, the ability to measure and control these spin properties has the potential to lead to transformative new technologies such as spintronics and quantum information processing. The goal of the research is to prepare and measure spin states through optical methods in a special type of semiconductor nanostructures known as coupled quantum dots (CQD). The ability to produce a robust initial state for quantum information operations is difficult; however, the CQD system may naturally be in desirable states after relaxation and emission of a photon. This research will characterize and use the emission from the CQD itself as a trigger indicating the spins are in the necessary configuration. The research provides students with training in various aspects of optics, photonics, spectroscopy, and basic semiconductor processing and characterization while participating in timely and technologically relevant research. One of the important broader impacts of the proposal is to recruit undergraduate students to engage in advanced research providing hands-on involvement in the operation of the laboratory.****TECHNICAL ABSTRACT****Robust control of spin in nanostructures will have broad scientific impacts, from advances in technology to probing fundamental quantum mechanics. The goal of the research is to prepare and measure entangled spin states through optical excitation in coupled quantum dots. Implementing quantum information processing requires the ability to identify, manipulate, and measure coupled quantum states. This program will impact the field by pursuing the use of excited state properties in coupled quantum dots (CQD) for spin preparation and measurement. These results will provide a natural route to spin manipulation through the use of pulsed laser techniques. The research will specifically address the excited state spectra through the use of optical polarization signatures and photon correlation measurements. Polarization signatures can offer a clear identification of specific charge and spin states, yet, a study of these signatures in the field of CQDs is still lacking. Similarly, selective excitation into higher energy states may provide a pathway for the preparation and coherent manipulation of coupled spins. Combining these techniques with photon correlation measurements will provide a straightforward method to select and study prepared spin states in CQDs. The research provides students with training in various aspects of optics, photonics, spectroscopy, and basic semiconductor processing and characterization while participating in timely and technologically relevant research. One of the important broader impacts of the proposal is to recruit undergraduate students to engage in advanced research providing hands-on involvement in the operation of the laboratory.

****非技术抽象****电子具有称为自旋的特性，其表现在许多方面都像微小的磁铁一样。 但是，与熟悉的棒磁体不同，当电子旋转测量时，它仅在两个方向之一中指向，有时称为“向上”或“ down”或像计算机位“ 1”或“ 0”。 除了这种二进制性质外，旋转还可以处于同时在两个方向“向上”和“向下”“指向”的状态。 在这样的状态下的一组旋转将包含一组经典位的所有可能组合。 一组量子位容纳如此大量信息的能力将提供计算能力的指数增加。 因此，测量和控制这些自旋特性的能力有可能导致变革性的新技术，例如旋转和量子信息处理。 该研究的目的是通过特殊类型的半导体纳米结构（称为耦合量子点（CQD））中的光学方法来制备和测量自旋状态。难以生产量子信息操作的强大初始状态的能力；然而，在放松和发射光子后，CQD系统自然可能处于理想状态。这项研究将以CQD本身的发射为特征，并将其作为触发器，表明旋转处于必要的配置中。 该研究为学生提供了光学，光子学，光谱和基本半导体处理和表征的各个方面的培训，同时参与了及时且与技术相关的研究。 该提案的重要广泛影响之一是招募本科生，参与提供实践参与实验室运作的高级研究。****技术摘要****对纳米结构中旋转的强大控制将产生广泛的科学影响，从技术的进步到探测基本量子机制的技术。 该研究的目的是通过耦合量子点中的光激发来准备和测量纠缠旋转状态。 实施量子信息处理需要识别，操纵和测量量子状态的能力。 该程序将通过在耦合的量子点（CQD）中追求激发状态性能来影响田地，以进行自旋准备和测量。 这些结果将通过使用脉冲激光技术提供自然的旋转操作途径。 这项研究将通过使用光学极化特征和光子相关测量值来特别解决激发态光谱。 极化标志可以清楚地识别特定电荷和自旋状态，但是，仍然缺乏对CQD领域的这些特征的研究。 同样，对高能状态的选择性激发可能为耦合旋转的制备和相干操纵提供途径。 将这些技术与光子相关测量结合在一起，将提供一种直接的方法，可以选择和研究CQD中准备的自旋状态。 该研究为学生提供了光学，光子学，光谱和基本半导体处理和表征的各个方面的培训，同时参与了及时且与技术相关的研究。 该提案的重要广泛影响之一是招募本科生，从事高级研究，提供动手参与实验室的运作。