Tang Qing, He Jia Xing, Chai Ya Qiang, Ouyang Peng Hui, Wei Lian Fu
Information Quantum Technology Laboratory, School of Information Science and Technology, International Cooperation Research Center of China Communication and Sensor Networks for Modern Transportation, Southwest Jiaotong University, Chengdu, 610031, China.
Sci Rep. 2025 Mar 17;15(1):9119. doi: 10.1038/s41598-025-89931-z.
Superconducting transmission line resonators (TLRs) have been widely applied to circuit quantum electrodynamical systems for superconducting quantum computation and single-photon detections. Recently, such a right-handed TLR has been generalized to electromagnetic metamaterials (MTMs), and its unconventional mode structure has been experimentally characterized (Wang et al. in Phys Rev Appl 11:054062, 2019). Here, we demonstrate another kind of MTM TLR, i.e., the superconducting quarter-wavelength composite right/left-handed (CRLH) TLRs composed of lumped elements. We design the devices and analyze their transport properties by developing a real-space approach, wherein the physical parameters at the device boundaries are utilized conveniently. Superconducting MTM TLRs with typical three unit cells were experimentally prepared by etching a superconducting aluminum film on a SiO[Formula: see text] substrate, and their microwave transport properties were measured at low temperatures of 50 mK. The results show that the modes spacing in such a quarter-wavelength CRLH-TLR is non-uniform, due to the nonlinear dispersion relation. This implies that it could be utilized to encode the superconducting qubits, analogously to the usual ones encoded by using the Josephson devices.
超导传输线谐振器（TLRs）已被广泛应用于用于超导量子计算和单光子探测的电路量子电动力学系统中。最近，这种右手TLR已被推广到电磁超材料（MTMs），并且其非常规模式结构已通过实验进行了表征（Wang等人，《物理评论应用》11:054062，2019）。在此，我们展示了另一种MTM TLR，即由集总元件组成的超导四分之一波长复合左右手（CRLH）TLR。我们通过开发一种实空间方法来设计器件并分析其传输特性，在该方法中可以方便地利用器件边界处的物理参数。通过在SiO₂衬底上蚀刻超导铝膜，实验制备了具有典型三个单元的超导MTM TLR，并在50 mK的低温下测量了它们的微波传输特性。结果表明，由于非线性色散关系，这种四分之一波长CRLH-TLR中的模式间距是不均匀的。这意味着它可用于编码超导量子比特，类似于使用约瑟夫森器件编码的普通量子比特。
