Relation between switching time distribution and damping constant in magnetic nanostructure

• Published in: Scientific reports Vol. 8; no. 1; pp. 13288 - 8
• Main Authors: Moon, Jung-Hwan, Lee, Tae Young, You, Chun-Yeol
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.09.2018; Nature Publishing Group
• Subjects: 639/301/119/997; 639/766/119/1001; Anisotropy; Humanities and Social Sciences; Magnetic fields; Markov analysis; multidisciplinary; Product design; Science; Science (multidisciplinary); Thermal stability
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-31299-4

It is widely known that the switching time is determined by the thermal stability parameters and external perturbations such as magnetic field and/or spin polarized current in magnetic nano-structures. Since the thermal stability parameter and switching time are crucial values in the design of spin-transfer torque magnetic random access memory, the measurement of the switching time is important in the study of the switching behavior of ferromagnetic nano-structures. In this study, we focus on the distribution of the switching time. Within the limit of a large energy barrier, a simple analytical expression between damping constant and anisotropy field with switching time distribution is obtained and confirmed by numerically solving the Fokker-Planck equation. We show that the damping constant and anisotropy field can be extracted by measuring the full width half maximum of the switching time distribution in the magnetic nano-structure devices. Furthermore, the present method can be applied to not only single nano-structure, but also inhomogeneous nano-structure arrays.