NER: Superconductor-nanotube Entangler

这项研究的目的是实现和测量相距较远的电子的量子纠缠。方法是从超导纳米线上提取库珀对(两个自然纠缠的电子)，并在空间上将它们分开，同时保持纠缠不变。这可以通过将超导体与两个表现出勒廷格液体性质的电引线接触来实现，这是一维系统的特征。使用碳纳米管，它自然是一维的，将绕过制造一维导线的困难。然后，组成库珀对的两个电子可以被强迫隧道进入两个不同的导线，并传输到一段距离之外。这种新的装置在理论上是可靠的，但还没有在实验上实现。如果成功，这项研究将导致第一次证明电子在一定距离内存在纠缠。这已经用光子实现了，但还没有用任何大质量粒子实现。在固态设备中使用电子将极大地简化许多技术要求，以构建用于超快传输量子信息的功能、可控和可扩展的设备。这样的设备最终将能够执行目前不可能完成的计算和加密任务。由于量子通信的未来关键依赖于纠缠，这项研究将提供极其重要的原理证明，它将是朝着开发可行的固态技术迈出的一大步。

The objective of this research is to achieve and measure the quantum entanglement of electrons which are far away from each other. The approach is to take a Cooper pair (two naturally entangled electrons) from a superconducting nanowire, and separate them spatially while keeping the entanglement intact. This can be achieved by contacting the superconductor with two electrical leads that exhibit Luttinger liquid properties, which are characteristic for one-dimensional systems. Using carbon nanotubes, which are naturally one-dimensional, will circumvent the difficulty of fabricating one-dimensional leads. The two electrons that make up the Cooper pair can then be forced to tunnel into two different leads, and transported some distance away. This novel device has been shown to be theoretically sound, but it has not been realized experimentally.If successful, this research would result in the first demonstration of entanglement at a distance for electrons. This has already been achieved with photons, but not with any massive particles. Using electrons in a solid-state device would immensely simplify many technical requirements for building functional, controllable and scalable devices for ultrafast transfer of quantum information. Such devices would ultimately be able to perform computational and cryptographic tasks that are currently impossible. As the future of quantum communication crucially relies on entanglement, this research would provide an extremely important proof of principle and it would represent a giant step towards developing a viable solid-state technology.