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

量子信息有望彻底改变科学技术的各个领域。它的实现主要受到退相干的阻碍，退相干是由于量子系统与其环境的不必要和不受控制的耦合而导致的信息丢失。该项目旨在通过应用旨在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来减少这种影响。这个想法与自旋回波效应密切相关，但在这里，研究人员应该考虑一种更通用和更强大的方法，旨在保持任意长的相干性。虽然保持量子相干性对于“量子存储器”应用至关重要，其中人们希望存储量子状态，但量子计算机需要额外的进步：应该可以可靠地处理量子信息。这是研究人员计划做出贡献的第二个领域，再次通过在NMR设置中使用动态解耦。为了实现这一目标，我们将联合收割机技术，如量子纠错码和退相干自由子空间与动态解耦。这将使我们能够将联合收割机信息处理与防止退相干结合起来。

Quantum information promises to revolutionize various fields of science and technology. Its implementation is hampered mostly by decoherence, the loss of information due to unwanted and uncontrolled couplings of the quantum system with its environment. This project aims at reducing this effect by applying 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 shall consider a much more general and robust approach, aimed at arbitrarily long coherence preservation. While preservation of quantum coherence is essential for “quantum memory” applications, where one wishes to store a quantum state, quantum computers require an additional advance: it should be possible to process quantum information reliably. This is the second area where the investigators plan to make a contribution, again by using dynamical decoupling in an NMR setting. To accomplish this goal, we will combine techniques such as quantum error correcting codes and decoherence-free subspaces with dynamical decoupling. This will enable us to combine information processing with its protection against decoherence.