International Collaboration in Chemistry: Decoherence control via quantum dynamical decoupling -- theory and experiment

南加州大学的Daniel Lidar由理论和计算化学项目的ICC奖资助，从事理论/实验合作，以开发用于量子信息处理的工具。Lidar是理论专家，而实验部分的工作由多特蒙德技术大学的Dieter Suter进行，他是由DFG资助的固体核磁共振（NMR）波谱学家。在核磁共振的背景下，他们正在研究量子技术面临的最棘手的问题之一：在任何量子系统与其环境不可避免的相互作用存在的情况下保持量子相干性。这个过程导致退相干，这有效地剥夺了量子系统的量子性。Lidar和Suter正在研究是否可以在任意长的时间内保持量子相干性。他们的方法是应用“动态解耦”脉冲序列，即设计用于重新聚焦或解耦量子系统与其环境之间相互作用的脉冲序列。这个想法与自旋回波效应密切相关，但在这里，研究人员考虑了一种更通用、更可靠的方法，旨在任意长时间保持相干性。支撑量子技术的是一门新的量子科学，其目的是在量子效应占主导地位的微观层面上控制物质。这种控制物质量子态的能力有可能使我们超越摩尔定律，即计算机处理速度的指数增长将在10-20年内结束。该提案是根据NSF 08-602：美国研究人员及其国外同行（ICC）之间的化学国际合作招标提交的。美国国家科学基金会和合作的国际资助机构共同审查并对该提案作出联合资助决定。NSF支持美国研究者的研究，DFG支持合作的外国研究者的研究。

Daniel Lidar of the University of Southern California is funded by an ICC award from the Theoretical and Computational Chemistry program to engage in a theoretical/experimental collaboration for the purpose of developing enabling tools for quantum information processing. Lidar is the theorist while the experimental portion of the work is carried out by Dieter Suter of the Technical University of Dortmund, a solid nuclear magnetic resonance (NMR) spectroscopist funded by the DFG for this research. In the context of NMR, they are investigating one of the toughest problems facing quantum technologies: that of maintaining quantum coherence in the presence of the inevitable interaction of any quantum system with its environment. This process leads to decoherence, which effectively robs a quantum system of its quantumness. Lidar and Suter are investigating the question whether one can maintain quantum coherence for arbitrarily long times. Their approach is to apply "dynamical decoupling" pulse sequences, i.e., pulse sequences designed to refocus or decouple the interaction between the quantum system and its environment. This idea is closely related to the spin-echo effect, but here the investigators consider a much more general and robust approach, aimed at arbitrarily long coherence preservation. Underpinning quantum technologies is a new quantum science, that aims to control matter at the microscopic level where quantum effects are dominant. This ability to control the quantum state of matter has the potential to take us beyond the point where Moore's Law for the exponential growth in computer processing speeds comes to an end in 10-20 years.The proposal was submitted in response to solicitation NSF 08-602: International Collaboration in Chemistry between US Investigators and their Counterparts Abroad (ICC). The NSF and the partnering international funding agency co-reviewed and made a joint funding decision on this proposal. NSF supports the research of the U.S. investigators while the DFG supports the research of the collaborating foreign investigator.