Entangled spin pairs in graphene ENTS

石墨烯为自旋电子学提供了真正独特的机会。碳的小原子序数导致自旋-轨道相互作用的强度极弱，自旋弛豫时间预计会很长。在石墨烯中，电子和核自旋之间的超精细相互作用非常弱，这是导致自旋电子器件自旋弛豫的另一种主要微观机制。此外，单层石墨提供了实现自旋过滤器的潜力，而不需要使用铁磁材料。实现这些全石墨烯自旋活性器件的可能性将是革命性的，因为它将解决基于降维系统的自旋电子学中长期存在的问题，如导电性失配问题。石墨烯也是自旋量子位(量子点)的理想宿主材料，因为自旋-轨道相互作用结合电子-声子耦合和与周围原子核的超精细相互作用所引起的自旋退相干的两个主要来源是已知的弱的。随着超导体和石墨烯混合体系中分离的纠缠自旋对的产生，可以预见到许多原始的可能性。这项任务的成功演示将是一项实验突破，促进了大量量子光学类型的实验在固态中进行。我们的项目通过研究石墨烯/超导体/铁磁混合系统中库珀对分裂和产生纠缠自旋对的几种方法来解决上述问题。石墨烯为这一目的提供了一种非常有前途的材料，但由于它是一种新材料，许多问题需要回答。我们的项目将以协作的方式处理这些开放问题，要么集体寻找解决方案，要么根据需要在节点之间划分任务。预计该项目的结果将是首次展示固态中的纠缠自旋对。

Graphene offers truly unique opportunities for spintronics. The small atomic number of carbon results in an extremely weak strength of spin-orbit interaction, and very long spin relaxation times are expected. The hyperfine interaction between the electron and the nuclear spins, the other main microscopic mechanism responsible for spin relaxation in spintronics devices, is very weak in graphene. Furthermore, single-layer graphite offers the potential to realize spin-filters without the need to use ferromagnetic materials. The possibility to realize these all-graphene spin-active devices would be revolutionary, in that it would solve long standing issues in spintronics based on reduced dimensionality system, such as the conductivity mismatch problem. Graphene is also an ideal host material for spin qubits (quantum dots) because the two major sources of spin decoherence caused by spin-orbit interaction in combination with electron-phonon coupling and hyperfine interaction with the surrounding nuclei are known to be weak. With the generation of separated entangled pairs of spins in hybrid systems between superconductors and graphene, lots of original possibilities can be envisioned. A successful demonstration of this task would be an experimental breakthrough facilitating a multitude of quantum optics type of experiments to be performed in solid state. Our project addresses the above issues by investigating several approaches of Cooper pair splitting and generation of entangled spin pairs in graphene/superconductor/ferromagnet hybrid systems. Graphene provides an exceptionally promising material for this purpose, but, since it is a new material, many questions need to be answered. Our project will work on these open problems in a collaborative manner, either by looking for solutions collectively or by dividing tasks between the nodes as needed. The outcome of the project is expected to be the first demonstration of entangled spin pairs in the solid state.