AI 中文总结
该研究提出一种四端约瑟夫森结，通过调控横向相位差可同时实现完美非局域自旋与电荷二极管效应，且响应鲁棒、调控性强，在超导自旋电子学中具应用潜力。
AI 中文摘要
我们从理论上研究了带有正常金属势垒的四端约瑟夫森结中的电荷与自旋输运。顶部和底部超导引线为等自旋三重态$p_y$波超导体，而左右引线为具有邻近诱导常规$s$波超导性的$p$波磁体。当顶部与底部引线间的横向宏观相位差设为零时，纵向偏置会产生纯横向自旋电流，具备100%的完美非互易性。值得注意的是，有限的横向相位差在保留完美自旋二极管效应的同时，还会诱导出完美电荷二极管效应，实现完全非互易的自旋与电荷输运。此外，自旋二极管效率随势垒所加栅极电压以及$p$波磁体的晶体学取向呈现尖锐的阶跃式切换，为控制二极管极性提供了独立且可实验实现的调控旋钮。该二极管响应对非对称界面耦合、非磁性无序、单重态与三重态配对强度的相对变化、温度及结尺寸均具有鲁棒性，表明该效应并非精细调谐参数的结果。这些发现确立了所提出的四端结为高度可调且结构鲁棒的平台，可用于无耗散、相位控制的自旋与电荷整流，在超导自旋电子学中具有潜在应用。
英文摘要
We theoretically investigate charge and spin transport in a four-terminal Josephson junction with a normal-metal barrier. The top and bottom superconducting leads are equal-spin triplet $p_y$-wave superconductors, while the left and right leads are $p$-wave magnets with proximity-induced conventional $s$-wave superconductivity. When the transverse macroscopic phase difference between the top and bottom leads is set to zero, a longitudinal phase bias generates a pure transverse spin current with perfect 100% nonreciprocity. Remarkably, a finite transverse phase difference preserves the perfect spin-diode effect while simultaneously inducing a perfect charge-diode effect, enabling fully nonreciprocal spin and charge transport. Moreover, the spin-diode efficiency exhibits sharp, step-like switching as a function of both the gate voltage applied to the barrier and the crystallographic orientation of the $p$-wave magnet, providing independent and experimentally accessible knobs for controlling the diode polarity. The diode response remains robust against asymmetric interface couplings, nonmagnetic disorder, variations in the relative singlet and triplet pairing strengths, temperature, and junction dimensions, demonstrating that the effect is not a consequence of fine-tuned parameters. These findings establish the proposed four-terminal junction as a highly tunable and structurally robust platform for dissipationless, phase-controlled spin and charge rectification, with potential applications in superconducting spintronics.
Comments13 pages, 6 figures
