NER: Decoherence and Quantum Computing in Nanoengineered Semiconductor Devices

该提案是针对NSE、NSF-0019而收到的。PI建议发展固态多体模拟技术来评估纳米半导体材料中核自旋和杂质束缚电子自旋的退相干、弛豫和相互作用性质。现代层状半导体异质结和量子阱，包括应变合金、能带结构和g因子工程，已被用于实现量子信息处理(量子计算)的最新设计。量子比特(量子比特)是精确定位的、同位素选择的杂质原子的核或束缚电子自旋。最近，已经证明这种结构实际上可以通过先进的分子束外延和光刻技术来制造。由于新的实验发展，包括光泵核磁共振极化检测和自旋极化电子行为与核极化的耦合，对半导体材料中极化自旋的研究也成为人们关注的焦点。一些实验工作正在进行中，以测量单自旋并实现最初的几个量子位的基于半导体自旋的量子计算。在自旋相互作用、控制、弛豫和退相干的理论建模和估计方面只有有限的进展。特别是对退相干的考虑，是固态半导体研究的一个新维度，在早期的研究中没有考虑到这一点。这一领域是开放的，开放的问题不仅是如何计算，而且是计算什么，以及与相干量子动力学有关的许多概念问题仍有待澄清。PIS的重点将是开发和应用理论技术，通过场论多体固态技术来研究这类系统中从控制到退相干的所有方面的量子动力学。希望这一探索性项目的成功将导致半导体研究和技术开发这一爆炸性增长领域的新突破。

This proposal was received in response to NSE, NSF-0019. The PI propose to develop solid-state many-body modeling techniques for evaluation of decoherence, relaxation, and interaction properties of nuclear and impurity-bound electron spins in nanoengineered semiconductor materials. Modern layered semiconductor heterostructures and quantum wells, involving strained alloys, band-structure and g-factor engineering, have been utilized in recent designs for realizations of quantum information processing (quantum computing). Quantum bits (qubits) are the nuclear or bound-electron spins of precisely positioned, isotopically selected impurity atoms. Recently, it has been demonstrated that such structures can be actually made by advanced MBE and lithography techniques. Consideration of polarized spins in semiconductor materials has become also of central interest owing to new experimental developments including optically pumped NMR detection of polarization and coupling of spin-polarized electronic behavior to nuclear polarization. Several experimental efforts are on the way to measure single spins and realize initial few-qubit semiconductor spin-based quantum computation. There has been only limited advancement in theoretical modeling and estimation of spin interactions, control, relaxation, and decoherence. The consideration of decoherence, in particular, is a new dimension in solid-state semiconductor research, not considered in earlier studies. The field is widely open with the open questions being not only how, but what to calculate, and with many conceptual issues remaining to be clarified, in relation to coherent quantum dynamics. PIs emphasis will be on developing and applying theoretical techniques to study all the aspects of quantum dynamics in such systems, from control to decoherence, by field-theoretical many-body solid-state techniques. It is hoped that success of this exploratory project will lead to new breakthroughs in an explosively growing field of semiconductor research and technology development.