On-line SPICE-SPIN+X Seminars
On-line Seminar: 23.09.2020 - 15:00 (CET)
- How small can we make it and what else can we use it for -
Hideo Ohno, Tohoku University
Development of spintronics nonvolatile nanodevices and their integration with CMOS circuits has resulted in realizing low-energy, yet high performance integrated circuits suitable for a number of applications such as Internet-of-Things (IoT), high-performance computing and artificial intelligence. Magnetic tunnel junction (MTJ), a spintronics device, plays a central role here, which has been shown to scale down to 20 nm with the perpendicular-easy-axis CoFeB-MgO system [1, 2]. I will first discuss the factors that limit the scalability of such MTJs. Then show how one can extend its scalability to the range of 4-8 nm and below [3, 4] by employing a new (and yet not so new) concept. Current-induced switching of magnetization and high thermal stability of these devices are also shown. I will then describe how one can use less stable MTJs for a novel form of computation, probabilistic computing, to address optimization problems. I show that one can formulate integer factorization as an optimization problem in such a way that the most preferred state in terms of energy gives the factorized result . If I have time I will touch upon proof-of-concept spintronics devices for artificial synapse as well as neuron for neuromorphic applications [6, 7].
Work done in collaboration with S. Fukami and the CSIS team. A portion of the work described here is a result of collaboration with A. Z. Pervaiz, K. Y. Camsari, and S. Datta of Purdue University. Supported in part by the ImPACT Program of CSTI, JST-OPERA JPMJOP1611 and Grant-in-Aid for Specially Promoted Research (17H06093).
 S. Ikeda, et al. Nature Materials, 9, 721 (2010).
 H. Sato, et al. IEDM 2013 and Appl. Phys. Lett. 105, 062403 (2014).
 K. Watanabe, et al. Nature Commun. 9, 663 (2018).
 B. Jinnai, et al. Appl. Phys. Lett. (Perspective), 116, 160501 (2020).
 W. A. Borders, et al. Nature 573, 390-393 (2019).
 W. A. Borders et al. Appl. Phys. Express 10, 013007 (2017).
 A. Kurenkov, et al. Advanced Materials 31, 1900636 (2019).