NER: Superconductor-nanotube Entangler

本研究的目的是实现和测量彼此相距较远的电子之间的量子纠缠。该方法是从超导纳米线中提取库珀对（两个自然纠缠的电子），并在保持纠缠完整的情况下将它们在空间上分开。这可以通过将超导体与表现出一维系统特征的卢廷格液体特性的两根电引线接触来实现。使用碳纳米管，自然是一维的，将避免制造一维引线的困难。然后，构成库珀对的两个电子可以被迫隧穿到两个不同的引线中，并传输一段距离。这种新装置在理论上是可行的，但还没有在实验中实现。如果成功，这项研究将首次证明电子在远距离上的纠缠。这已经在光子上实现了，但还没有在任何大质量粒子上实现。在固态设备中使用电子将极大地简化许多技术要求，以构建用于超快速量子信息传输的功能、可控和可扩展设备。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至关重要地依赖于纠缠，这项研究将提供一个极其重要的原理证明，它将代表着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.