[9p-PB1-1~80] 10 Spintronics and Magnetics (Poster)

▲ [9p-PB1-47] The effect of voltage on reservoir computing performance of a spin torque oscillator

〇Sumito Tsunegi¹, Tomohiro Taniguchi¹, Shinji Miwa², Kohei Nakajima^3,4, Kay Yakushiji¹, Akio Fukushima¹, Shinji Yuasa¹, Hitoshi Kubota¹ (1.AIST, 2.ISSP, The Univ. of Tokyo, 3.The Univ. of Tokyo, 4.JST PRESTO)

Keywords:reservoir computing, spintronics, spin torque oscillator

Spin torque oscillator (STO) driven by highly nonlinear motion of magnetization can generate transient dynamics, which can be useful to realize physical reservoir computing. As a figure of merit of the reservoir computing, memory capacity C_STM is widely used, which can be estimated from short-term memory task. We evaluated C_STM of STOs in both simulation and experiment. From those previous works, it is expected that the optimum pulse duration Δt at which C_STM exhibits a maximum decreases at a high voltage and increases at a low voltage. In other words, the memory capacity will exhibit maximum at high (low) pulse voltage Vint when the pulse duration is short (long). In this study, we performed systematically the short memory task to evaluate the memory capacity in vortex-STO as functions of pulse duration and voltage. As a result, a maximum of the memory capacity shifts from high to low Vint as Δt increases, which is consistent with our expectation.