CM Seminar- “Spin dynamics and transport in emerging magnetic materials” with Prof. Kab-Jin Kim (KAIST)
Physics Seminar
December 12, 2024
10:00 AM - 11:00 AM
Location
SES 3182
Calendar
Download iCal FileSpin dynamics and transport in emerging magnetic materials
Kab-Jin Kim
Department of Physics, KAIST, Daejeon 34141, Republic of Korea
Magnetic solitons, such as magnetic domain walls, skyrmions, vortices, and Bloch lines, represent distinctive spin configurations within magnets and play a crucial role in modern magnetism and spintronics [1]. Investigating the dynamics of these solitons is pivotal, as it not only unveils new physics [2,3] but also propels the development of magnetic devices [4,5]. Concurrently, spin transport is another essential facet of spintronics research. Efforts to generate pure spin currents have spurred investigations into various spin orbit effects, including the spin Hall effect and Rashba effect, leading to intriguing physical phenomena and diverse magnetoresistances [6].
In this presentation, I will share insights from my journey in spintronics research, focusing on uncovering novel phenomena in spin dynamics and transport. The first part focuses on spin dynamics across a broad dynamic range, particularly emphasizing research on magnetic domain wall dynamics. Discussions encompass the creep and hopping dynamics governing slow regimes [7] and extend to the fast and ultrafast dynamics achievable in emerging magnetic materials, such as ferrimagnets and antiferromagnets [8]. In the second part, I will present our recent findings on spin transport phenomena. We employed THz time-domain spectroscopy to reveal the fundamental magnetotransport characteristics in magnetic materials undergoing phase transitions [9,10]. Additionally, we will demonstrate how the utilization of magnetic phase transitions can lead to the generation of large spin current bursts, the underlying mechanism of which transcends the orthodox spin torque theory [11].
[1] H.B. Braun, Adv. Phys., 61, 1 (2012)
[2] I.M. Miron et al., Nature, 476, 189 (2011); L. Liu et al., Science, 336, 555 (2012);
[3] S. Emori et al., Nat. Mater., 12, 611 (2013); K.-S. Ryu et al., Nat. Nanotech., 8, 527 (2013)
[4] S. Parkin et al., Nat. Nanotech., 10, 195 (2015)
[5] Z. Luo et al., Nature, 579, 214 (2020)
[6] A. Manchon et al., Rev. Mod. Phys., 91, 035004 (2019)
[7] K.-J. Kim et al., Nature, 458, 740 (2009); J.-C. Lee et al., Phys. Rev. Lett., 107, 067201 (2012); M. Song et al., Adv. Mater., 34, 2203275 (2022)
[8] Y. Yoshimura et al., Nat. Phys. 7, 157 (2016); K.-J. Kim et al., Nat. Mater. 16, 1187 (2017)\
[9] J.-H. Park et al., Sci. Rep. 11, 20884 (2021)
[10] J.-H. Park et al., “Unraveling the origin of conductivity change in FeRh phase transitions”, Comm. Mater. 5, 250 (2024)
[11] T. Lee et al., “observation of longitudinal spin pumping”, Nature, in press.
Date posted
Dec 6, 2024
Date updated
Dec 6, 2024