标题： 基于多维频段纠缠的量子密钥分发网络 显示英文标题

标题： Multi-dimensional frequency-bin entanglement-based quantum key distribution network

摘要： 量子网络增强了量子通信方案，并在大范围区域内连接多个用户。 利用高维量子态——即 qu-d-its——相比量子比特，能够实现信息的更密集传输，并且对噪声具有更高的鲁棒性。 频率编码使我们在电信波长下能够访问此类 qu-d-its，同时使用现成的光纤设备处理量子信息。 我们使用一个低自由光谱范围的硅微谐振器，通过自发四波混频生成维度 d=2（量子比特）和 d=3（三重态）的贝尔态，以实现并优化基于多维频率子区间纠缠的量子密钥分发网络。 我们根据连接长度，通过基于傅里叶变换脉冲整形和电光调制的单一光纤硬件，调节光源（通过泵浦功率）、信号处理（通过符合窗口大小）和 qu-d-it 编码（d=2 或 3）。 我们实现了使用三重态的安全密钥速率为 1374 bit/s，并估计使用量子比特的通信距离为 295 km。 我们最多访问 80 个频率模式，从而产生 21 个量子信道，这些信道能够在超过 21 小时内提供稳定的通信。 我们展示了一个基于多维纠缠的量子密钥分发网络中的竞争力通信范围，这为在城市光纤链路上部署更大维度的实现奠定了基础。 显示英文摘要

摘要： Quantum networks enhance quantum communication schemes and link multiple users over large areas. Harnessing high dimensional quantum states - i.e. qu-d-its - allows for a denser transfer of information with increased robustness to noise compared to qubits. Frequency encoding enables access to such qu-d-its at telecom wavelengths, while manipulating quantum information with off-the-shelf fibered devices. We use a low free spectral range silicon microresonator to generate Bell states of dimension d=2 (qubits) and d=3 (qutrits) via spontaneous four wave mixing, to implement and optimize a multi-dimensional frequency-bin entanglement-based quantum key distribution network. We tune the source (via pump power), the signal processing (via coincidence window size) and qu-d-it encoding (d=2 or 3) using a single fibered hardware based on Fourier-transform pulse shaping and electro-optic modulation depending on interconnection lengths. We achieve secure key rates of 1374 bit/s with qutrits, and estimate the communication range to 295 km with qubits. We access up to 80 frequency modes, resulting in 21 quantum channels, that provide stable communication over more than 21 hours. We demonstrate a competitive communication range in a multi-dimensional entanglement-based quantum key distribution network that lays the groundwork for larger dimensionality implementations deployed on metropolitan fiber links.