Coherent Nanotechnology Quantum Devices for Information Processing

在美国国家科学基金会ECS分部授予的为期一年的探索性研究小额拨款(SGER)中，我们探索了纳米技术设备中相干量子效应的新概念。我们设想了几种基于耦合相干量子现象的新型固态器件，这些器件在计算和通信方面具有潜在的应用价值，并通过理论研究探讨了它们的实用性。随着这一初步的成功，我们现在提议继续这些研究，对这些现象进行更广泛和更精确的分析，并启动一个耦合实验计划来证明其可行性。显示出量子计算机最有希望的纳米技术结构是基于被捕获在由III-V或硅制造的门控量子点阵列中的交换耦合电子的自旋。所提出的量子计算机能够在108赫兹的两个量子比特的运算率下在相干时间内进行105次运算。它可以很容易地扩展到大量的元素，大约106个量子比特的数量级，并且可以利用平面结构进行电重构。毫无疑问，这种设备可以使用《国际半导体技术路线图，1999版》中规定的70纳米技术节点实现的技术来制造。我们已经与业界建立了合作，一旦我们证明了可行性，就希望利用这种纳米技术。为了充分检验我们概念的潜力，我们建议通过分析设备的物理参数来产生所需的能量结构和相邻设备元素之间的耦合强度，通过调查相干的限制，并通过模拟设备的操作来将其作为水量子计算机进行操作，来进行全面的研究。我们还建议进行一项实验计划，以制造和测试这些设备的基本原型，以证明其可行性。理论研究和实验研究之间的合作将产生一种技术上有趣的、具有潜在商业意义的纳米设备结构。这项研究将与一个教育项目相结合，该项目为研究生提供跨学科研究，并在北卡罗来纳州立大学电气和计算机工程系内开发课程，在研究生水平上介绍量子信息处理。

In a one-year small grant for exploratory research (SGER) granted by the ECS Divisionof NSF, we have explored new concepts for coherent quantum effects in nanotechnologydevices. We have conceived of several new solid-state devices based on coupled coherentquantum phenomena that are potentially useful for computing and communications, andinvestigated their practicality through theoretical studies. With this initial success, wenow propose to continue these studies with a more extensive and precise analysis of thephenomena and to initiate a coupled experimental program to show feasibility.The nanotechnology structure that shows most promise for a quantum computer is basedon the spin of exchange coupled electrons trapped in an array of gated quantum dotsfabricated in either III-V or silicon. The proposed quantum computer is capable of 10 5operations within the coherence time at a two-qubit operation rate at 10 8 Hz. It is readilyscalable to a large number of elements, on the order of ~10 6 qubits, and electricallyreconfigurable utilizing a planar architecture. This device is unquestionablymanufacturable using technology enabled by the 70-nm technology node as specified inthe "International Technology Roadmap for Semiconductors, 1999 Edition". We haveestablished collaborations with industry that wish to take advantage of thisnanotechnology once we have shown feasibility.To fully examine the potential of our concepts, we propose to conduct a comprehensivestudy by analyzing the physical parameters of the devices to generate the desired energystructure and coupling strength among neighboring device elements, by investigating thelimitations to coherence, and by simulating the operation of the device to operate it as aquantum computer. We further propose to undertake an experimental program tofabricate and test elementary prototypes of these devices to demonstrate feasibility.Collaboration between the theoretical and experimental studies should result in a nano-devicestructure that is technically interesting and potentially important for commercialuse.This research will be coupled to an educational program that provides interdisciplinaryresearch for graduate students and for the development of courses that introduce quantuminformation processes at the graduate level within the Electrical and ComputerEngineering Department at North Carolina State University.