Ⅰ. INTRODUCTION 1 Ⅱ. THEORTICAL BACKGROUND 2.1 DW types in perpendicular magnetic anisotropy 3 2.2 Landau-Lifshitz and Gilbert equation (LLG equation) 8 2.3 Field-induced pinning / depinning of DW 10 2.4 Anomalous Hall Effect 13 2.5 Polar Magneto-Optic Kerr microscopy 15 Ⅲ. DEVICE FABRICATION TECHNIQUE 3.1 DC magnetron sputtering 20 3.2 Photolithography 24 3.3 Ion beam milling system 26 3.4 E-beam evaporator 28 Ⅳ. RESULTS & DISCSSUION 4.1 Film characterization 30 4.2 Memristive functionality originated from DW movement 35 4.3 Spintronics synapses for artificial neural network 38 4.4 Correlation between the change of R_H and DW pinning process 42 4.5 The number of multi-states in R_H as a function of field intensity 45 4.6 The variation of R_H for the different τ_d of field 47 4.7 R_H in various shape according to the number of field pulses 49 4.8 STDP learning rules related with pulse conditions 53 4.9 Various shape of R_H by modulating the polarities 56 4.10 Potentiation and depression of R_H with DW motion 59 Ⅴ. CONCLUSION 62 Ⅵ. REFERENCE 63