Wang Zhao-An, Zeng Xiao-Dong, Wang Yi-Tao, Ren Jia-Ming, Ao Chun, Li Zhi-Peng, Liu Wei, Guo Nai-Jie, Xie Lin-Ke, Liu Jun-You, Ma Yu-Hang, Wu Ya-Qi, Luo Xi-Wang, Wang Shuang, Tang Jian-Shun, Li Chuan-Feng, Guo Guang-Can
CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, China.
Anhui Province Key Laboratory of Quantum Network, University of Science and Technology of China, Hefei, China.
Nat Commun. 2025 Aug 20;16(1):7780. doi: 10.1038/s41467-025-63114-w.
Investigating physical models with photonic synthetic dimensions has been generating great interest in vast fields of science. The rapidly developing thin-film lithium niobate (TFLN) platform, for its numerous advantages including high electro-optic coefficient and scalability, is well compatible with the realization of synthetic dimensions in the frequency together with spatial domain. While coupling resonators with fixed beam splitters is a common experimental approach, it often lacks tunability and limits coupling between adjacent lattices to sites occupying the same frequency domain positions. Here, on the contrary, we conceive the resonator arrays connected by electro-optic tunable Mach-Zehnder interferometers in our configuration instead of fixed beam splitters. By applying bias voltage and RF modulation on the interferometers, our design extends such coupling to long-range scenario and allows for continuous tuning on each coupling strength and synthetic effective magnetic flux. Therefore, our design enriches controllable coupling types that are essential for building programmable lattice networks and significantly increases versatility. As the example, we experimentally fabricate a two-resonator prototype on the TFLN platform, and on this single chip we realize well-known models including tight-binding lattices, the Hall ladder and Creutz ladder. We directly observe the band structures in the quasi-momentum space and important phenomena such as spin-momentum locking, flat band and the Aharonov-Bohm cage effect. These results demonstrate the potential for convenient simulations of more complex models in our configuration.
利用光子合成维度研究物理模型在众多科学领域引起了极大的兴趣。快速发展的薄膜铌酸锂（TFLN）平台具有诸多优势，包括高电光系数和可扩展性，非常适合在频率和空间域实现合成维度。虽然使用固定分束器耦合谐振器是一种常见的实验方法，但它通常缺乏可调性，并且将相邻晶格之间的耦合限制在占据相同频域位置的位点。相反，在我们的配置中，我们设想用电光可调马赫 - 曾德尔干涉仪连接谐振器阵列，而不是固定分束器。通过在干涉仪上施加偏置电压和射频调制，我们的设计将这种耦合扩展到远程场景，并允许对每个耦合强度和合成有效磁通量进行连续调谐。因此，我们的设计丰富了构建可编程晶格网络所必需的可控耦合类型，并显著提高了通用性。作为示例，我们在TFLN平台上实验制造了一个双谐振器原型，并且在这个单芯片上我们实现了包括紧束缚晶格、霍尔梯和克鲁兹梯等著名模型。我们直接观察到准动量空间中的能带结构以及诸如自旋 - 动量锁定、平带和阿哈罗诺夫 - 玻姆笼效应等重要现象。这些结果证明了在我们的配置中方便模拟更复杂模型的潜力。
