Chiral Excitations in Spintronics
Tao Yu, Max Planck Institute for the Structure and Dynamics of Matter
August 6, 2021
We recently witnessed the discovery of various chiral interactions between magnetic, phononic, electronic, and photonic excitations in spintronics that mediate the excitation of quasiparticles into a single direction, leading to phenomena such as chiral spin and phonon pumping, chiral spin Seebeck, magnonic skin, magnon trap, magnon Doppler, and spin diode effects [1-6]. Intriguing analogies with electric counterparts in the nano-optics and plasmonics exists. In this talk, I will present a unified electrodynamic picture for dynamical chirality in spintronics and compare it with that in nano-optics and plasmonics . Based on the general theory, I subsequently review the theoretical progress and experimental evidence of chiral interaction between various excitations in magnetic, photonic, electronic, and phononic nanostructures at GHz time scales.
 T. Yu*, G. E. W. Bauer, and Z. C. Luo, "Chiral Excitations in Spintronics", review article for Physics Reports.
 T. Yu, Y. M. Blanter, and G. E. W. Bauer, “Chiral pumping of spin waves ”, Phys. Rev. Lett. 123, 247202 (2019).
 T. Yu, Y.-X. Zhang, S. Sharma, X. Zhang, Y. M. Blanter, and G. E. W. Bauer, “ Magnon Accumulation in Chirally Coupled Magnets”, Phys. Rev. Lett. 124, 107202 (2020).
 X. Zhang, G. E. W. Bauer, and T. Yu*, “ Unidirectional Pumping of Phonons by Magnetization Dynamics”, Phys. Rev. Lett 125, 077203 (2020).
 T. Yu and G. E. W. Bauer, “Noncontact Spin Pumping by Microwave Evanescent Fields ”, Phys. Rev. Lett 124, 236801 (2020).
 T. Yu, C. Wang, M. Sentef, and G. E. W. Bauer, “Spin-Wave Doppler Shift by Magnon Drag in Magnetic Insulators”, Phys. Rev. Lett. 126, 137202 (2021).