基于交变磁体的超导量子比特
Superconducting qubit based on altermagnets
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中文总结 AI 辅助
本研究利用交变磁体的约瑟夫森效应，设计可编程约瑟夫森势，提出一种新型transmon类超导量子比特，通过双库珀对隧穿实现大非谐性和抗退相干，并利用宇称保护抑制电荷噪声，为高性能超导量子比特开辟新途径。
中文摘要 AI 辅助
交变磁体具有净磁化强度为零和动量依赖的自旋劈裂的特点，为下一代约瑟夫森器件提供了一个有前景的平台。在此，我们利用超导体-交变磁体-超导体结中的约瑟夫森效应，并展示了如何通过器件设计来工程化预定的电流-相位关系。基于这些利用交变磁性的可编程约瑟夫森势，我们提出了一类新型的类transmon超导量子比特，它通过相干的双库珀对隧穿，将大的非谐性与增强的抗退相干鲁棒性相结合。我们表明，在$2\phi$结区域，这种量子比特由于宇称保护而对电荷噪声具有内在的保护作用。磁通量可用于精确控制量子比特，并且在适当的偏置下，这种架构进一步抑制了电荷和磁通噪声。我们的结果确立了交变磁体作为约瑟夫森势工程的多功能平台，并为实现兼具高相干性、大非谐性和宽可调性的高性能超导量子比特开辟了新途径。
英文摘要
Altermagnets, characterized by vanishing net magnetization and momentum-dependent spin splitting, provide a promising platform for next-generation Josephson devices. Here, we exploit the Josephson effect in superconductor-altermagnet-superconductor junctions and show how to engineer prescribed current-phase relations by device design. Based on these programmable Josephson potentials utilizing altermagnetism, we propose a new class of superconducting qubits that combine large anharmonicity with enhanced robustness against decoherence via coherent two-Cooper-pair tunneling. We show that in the $2ϕ$-junction regime, this kind of qubit is intrinsically protected against both charge and flux noise due to parity protection. Magnetic flux can be used to precisely control the qubit and, under appropriate bias, this architecture further suppresses charge and flux noise. Our results establish altermagnets as a versatile platform for Josephson-potential engineering and open a new route toward high-performance superconducting qubits combining high coherence, large anharmonicity, and broad tunability.
发表机构
- Xi’an Jiaotong University（西安交通大学）
- RIKEN（理化学研究所）
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