Daido Akito, Ikeda Yuhei, Yanase Youichi
Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Institute for Molecular Science, Okazaki 444-8585, Japan.
Phys Rev Lett. 2022 Jan 21;128(3):037001. doi: 10.1103/PhysRevLett.128.037001.
Stimulated by the recent experiment [F. Ando et al., Nature (London) 584, 373 (2020).NATUAS0028-083610.1038/s41586-020-2590-4], we propose an intrinsic mechanism to cause the superconducting diode effect (SDE). SDE refers to the nonreciprocity of the critical current for the metal-superconductor transition. Among various mechanisms for the critical current, the depairing current is known to be intrinsic to each material and has recently been observed in several superconducting systems. We clarify the temperature scaling of the nonreciprocal depairing current near the critical temperature and point out its significant enhancement at low temperatures. It is also found that the nonreciprocal critical current shows sign reversals upon increasing the magnetic field. These behaviors are understood by the nonreciprocity of the Landau critical momentum and the change in the nature of the helical superconductivity. The intrinsic SDE unveils the rich phase diagram and functionalities of noncentrosymmetric superconductors.
受近期实验[F. 安藤等人，《自然》（伦敦）584, 373 (2020)。NATUAS0028 - 083610.1038/s41586 - 020 - 2590 - 4]的启发，我们提出了一种导致超导二极管效应（SDE）的内在机制。SDE是指金属 - 超导体转变时临界电流的非互易性。在各种临界电流机制中，解配对电流已知是每种材料所固有的，并且最近在几个超导系统中已被观测到。我们阐明了临界温度附近非互易解配对电流的温度标度，并指出其在低温下有显著增强。还发现非互易临界电流在增加磁场时会出现符号反转。这些行为可以通过朗道临界动量的非互易性以及螺旋超导性质的变化来理解。这种内在的SDE揭示了非中心对称超导体丰富的相图和功能。
