Recent developments in spintronic devices based on current-induced domain wall motion, including the realization of domain-wall logic operators [1], and the demonstration of unconventional computing characteristics at the nanoscale [2], have provided a significant contribution toward the implementation of magnetic racetrack applications [3-4], which hold great promise for the realization of 3D memory and logic architectures [5-6].

In this seminar, I will discuss our recent progress toward the implementation of domain-wall-based racetrack nanodevices, in terms of materials development, device engineering for advanced functionalities, and realization of working memory devices. First, we have recently introduced a new class of L10 binary alloys based on Al and 5d transition metals, which generate large spin-orbit torques and promote very efficient motion of domain walls driven by short current pulses [7]. Second, we have realized ferromagnetic-synthetic antiferromagnetic lateral junctions for improved domain-wall stability and efficient domain-wall injection in racetrack nanodevices [8]. We have also developed several key innovations that allow to dynamically manipulate domain walls at the nanoscale [9-10], thus enhancing the functionalities of conventional nanowire racetrack devices, including the possibility to compress and de-compress magnetic domain-wall bits, using either the passive variation of the current density which drives the domain walls, or the active control of a localized bias current [11]. Finally, I will present our latest results in terms of practical implementation of all-electrical domain-wall nanodevices for conventional and non-conventional memory technology [2].

[1]  Z. C. Luo, A. Hrabec, T. P. Dao, G. Sala, S. Finizio, J. Feng, S. Mayr, J. Raabe, P. Gambardella and L. J. Heyderman, Nature 579, 214 (2020).
[2]  J.-C. Jeon, A. Migliorini, J. Yoon, J. Jeong, and S. P. P. Parkin, Science 386, 315 (2024).
[3]  S. S. P. Parkin, M. Hayashi and L. Thomas, Science 320, 190 (2008).
[4]  S. S. P. Parkin and S.-H. Yang, Nat. Nanotechnol. 10, 195 (2015).
[5]  K. Gu, Y. Guan, B. K. Hazra, H. Deniz, A. Migliorini, W. Zhang, and S. P. P. Parkin, Nat. Nanotechnol. 17, 1065 (2022).
[6]  L. Skoric, C. Donnelly, A. Hierro-Rodriguez, M. A. Cascales Sandoval, S. Ruiz-Gómez, M. Foerster, M. A. Niño, R. Belkhou, C. Abert, D. Suess, and A. Fernández-Pacheco, ACS Nano 16, 8860 (2022).
[7]  P. Wang, A. Migliorini, S.-H. Yang, J.-C. Jeon, I. Kostanovskiy, H. Meyerheim, H. Han, H. Deniz, and S. P. P. Parkin, Adv. Mater. 34, 2109406 (2022).
[8]  J. Yoon, S.-H. Yang, J.-C. Jeon, A. Migliorini, I. Kostanovskiy, T. Ma, and S. P. P. Parkin, Nat. Nanotechnol. 17, 1183 (2022).
[9]  S. P. P. Parkin, J.-C. Jeon, A. Migliorini, U.-H. Pi, US Patent US2023/0298649 A1 (2023).
[10]  S. P. P. Parkin, J.-C. Jeon, A. Migliorini, U.-H. Pi, US Patent US2023/0274772 A1 (2023).
[11]  J.-C. Jeon, A. Migliorini, L. Fischer, J. Yoon, and S. P. P. Parkin, ACS Nano 18, 14507 (2024).