L'Institut de recherche interdisciplinaire de Grenoble (Irig) est un institut thématique de la Direction de la Recherche Fondamentale du CEA.
Notre Institut est composé de 5 départements
Les 10 Unités Mixtes de Recherches de l'Irig
Publications, Thèses soutenues, Prix et distinctions
Vendredi 13 octobre 2023 de 10:00 à 12:00, Salle de séminaire 445, bâtiment 1005, CEA-Grenoble (access needs CEA pass)
Magnetoresistive sensors can deliver high sensitivity and spatial resolution in magnetic field detection, ideal to leverage applications in navigation, robotics or biomedicine. Being able to manipulate the device’s properties, as needed and during operation, has the potential to push further the limits of performance, and broaden applications of spintronic sensors. In this talk, two approaches to engineer these tuneable magnetic sensors will be introduced. One focus on local modification of the sensing layer magnetic anisotropy by nano-inclusions, with direct impact on linearity and coercivity. The second explores light as an external trigger to change the reference axis orientation and thus alter the sensitive direction. The discussion will include considerations regarding the tuning of the thin-film multilayers or of the patterned geometries to demonstrate these concepts. Such strategies open pathways to design versatile sensing devices with on-demand tuneable characteristics.
Magnetic tunnel junction (MTJ) serves as functional devices for various applications. Magnetic sensors and nonvolatile memories with MTJs are commercially available and its applications to unconventional computing has recently gathered a growing attention. In this seminar, I will present our recent work on MTJs to be applied for nonvolatile memory compatible with deeply-scaled semiconductor technologies and probabilistic computing that addresses computationally hard problems. For nonvolatile memory applications, it is crucial to establish a technology to exhibit high performance at ultrasmall scale down to less than 10 nm, or X nm. We have shown that utilization of shape anisotropy  and magneto-static coupling  both of which become evident in X-nm regime allows the MTJs to meet the requirements for Flash-like  and SRAM-like  applications. For probabilistic computing, MTJs are designed to generate random telegraph noise under thermal fluctuations, constituting the probabilistic bits . We have shown proof-of-concepts of the probabilistic computers with MTJs performing combinatorial optimization , machine learning , and quantum simulation . We have also revealed key physics to enhancing the performance of MTJs for large-scale problems [8,9]. The work has been carried out in collaboration with H. Ohno, B. Jinnai, J. Igarashi, S. Kanai, W. A. Borders, K. Hayakawa, K. Kobayashi, H. Kaneko of Tohoku University as well as S. Datta of Purdue University and K. Y. Camsari of the UC Santa Barbara. The work is supported in part by the JST-OPERA JPMJOP1611, JST-CREST JPMJCR19K3, JST-AdCORP JPMJKB2305, MEXT X-NICS JPJ011438, and JSPS KAKENHI 19H05622.  K. Watanabe et al., Nat. Commun. 9, 663 (2018).  B. Jinnai et al., IEDM2020, 24.6.1 (2020).  B. Jinnai et al., IEDM2021, 2.6.1 (2021).
 K. Y. Camsari et al., Phys. Rev. X 7, 031014 (2017).  W. A. Borders et al., Nature 573, 390 (2019).
 J. Kaiser et al., Phys. Rev. Appl. 17, 014016 (2022).  A. Grimardi et al., IEEE IEDM 2022, 22.4 (2022).
 S. Kanai et al., Phys. Rev. B 103, 094423 (2021).  K. Hayakawa et al., Phys. Rev. Lett. 126, 117202 (2021).Plus d'information :https://www.spintec.fr/seminars-two-seminars-on-magnetoresistive-sensors-and-magnetic-tunnel-junctions/
Access: Persons who do not have a CEA pass must request an entry authorization sufficiently in advance, before October 05th at
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Acteur majeur de la recherche, du développement et de l'innovation, le CEA intervient dans quatre grands domaines : énergies bas carbone, défense et sécurité, technologies pour l’information et technologies pour la santé.