Vienna Center for Quantum Science and Technology, Faculty of Physics, University of Vienna, Vienna, Austria.
Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
Nature. 2018 Apr;556(7702):473-477. doi: 10.1038/s41586-018-0036-z. Epub 2018 Apr 25.
Entanglement, an essential feature of quantum theory that allows for inseparable quantum correlations to be shared between distant parties, is a crucial resource for quantum networks . Of particular importance is the ability to distribute entanglement between remote objects that can also serve as quantum memories. This has been previously realized using systems such as warm and cold atomic vapours, individual atoms and ions, and defects in solid-state systems. Practical communication applications require a combination of several advantageous features, such as a particular operating wavelength, high bandwidth and long memory lifetimes. Here we introduce a purely micromachined solid-state platform in the form of chip-based optomechanical resonators made of nanostructured silicon beams. We create and demonstrate entanglement between two micromechanical oscillators across two chips that are separated by 20 centimetres . The entangled quantum state is distributed by an optical field at a designed wavelength near 1,550 nanometres. Therefore, our system can be directly incorporated in a realistic fibre-optic quantum network operating in the conventional optical telecommunication band. Our results are an important step towards the development of large-area quantum networks based on silicon photonics.
纠缠是量子理论的一个基本特征，它允许在遥远的双方之间共享不可分割的量子相关性，是量子网络的关键资源。特别重要的是能够在远程物体之间分配纠缠，这些物体也可以作为量子存储器。这以前是使用诸如温暖和冷原子蒸气、单个原子和离子以及固态系统中的缺陷等系统来实现的。实际的通信应用需要结合几个有利的特点，例如特定的工作波长、高带宽和长存储寿命。在这里，我们引入了一种纯粹的基于微机电系统的固态平台，其形式是由纳米结构硅梁制成的基于芯片的光机械谐振器。我们在通过 20 厘米隔开的两个芯片上创建并演示了两个微机械振荡器之间的纠缠。纠缠的量子态通过设计波长附近 1550 纳米的光场分布。因此，我们的系统可以直接集成到在传统光通信波段工作的现实光纤量子网络中。我们的结果是朝着基于硅光子学的大面积量子网络发展迈出的重要一步。
