Sivakumar Pranava K, Ahari Mostafa T, Kim Jae-Keun, Wu Yufeng, Dixit Anvesh, de Coster George J, Pandeya Avanindra K, Gilbert Matthew J, Parkin Stuart S P
Max Planck Institute of Microstructure Physics, 06120 Halle (Saale), Germany.
Materials Research Laboratory, The Grainger College of Engineering, University of Illinois, Urbana-Champaign, Illinois 61801 USA.
Commun Phys. 2024;7(1):354. doi: 10.1038/s42005-024-01825-0. Epub 2024 Oct 28.
Superconducting diode effects have recently attracted much attention for their potential applications in superconducting logic circuits. Several pathways have been proposed to give rise to non-reciprocal critical currents in various superconductors and Josephson junctions. In this work, we establish the presence of a large Josephson diode effect in a type-II Dirac semimetal 1T-PtTe facilitated by its helical spin-momentum locking and distinguish it from extrinsic geometric effects. The magnitude of the Josephson diode effect is shown to be directly correlated to the large second-harmonic component of the supercurrent. We denote such junctions, where the relative phase between the two harmonics can be tuned by a magnetic field, as 'tunable second order -junctions'. The direct correspondence between the second harmonic supercurrents and the diode effect in 1T-PtTe junctions at relatively low magnetic fields makes it an ideal platform to study the Josephson diode effect and Cooper quartet transport in Josephson junctions.
超导二极管效应因其在超导逻辑电路中的潜在应用，最近备受关注。人们已经提出了几种途径，以在各种超导体和约瑟夫森结中产生非互易临界电流。在这项工作中，我们证实了在II型狄拉克半金属1T-PtTe中，由于其螺旋自旋动量锁定而存在大的约瑟夫森二极管效应，并将其与外在几何效应区分开来。约瑟夫森二极管效应的大小与超电流的大二阶谐波分量直接相关。我们将这种两个谐波之间的相对相位可通过磁场调节的结称为“可调二阶π结”。在相对低磁场下，1T-PtTe结中二阶谐波超电流与二极管效应之间的直接对应关系，使其成为研究约瑟夫森结中约瑟夫森二极管效应和库珀四重态输运的理想平台。
