Chirality dependence of spin current in spin pumping

Abstract

Chirality of magnons is an intrinsic degree of freedom that characterizes the handedness of spin precession around its equilibrium direction. This commentary summarizes recent progress on spin pumping by ferromagnetic resonance in magnetic heterostructures. In particular, the commentary highlights one fundamental issue in spin pumping: the chirality dependence of the spin current.

Real-time observation of coherent chiral spin waves

“…While antiferromagnets have been suggested for versatile magnonic platform because of the coexistence of right-and lefthanded spin waves, their energetic degeneracy poses challenges for observation through spectral measurements, limiting their applicability. Recent observations of distinct spin wave handedness within the gigahertz regime have reported 5 Antiferromagnets, distinguished from ferromagnets by an alternating ordering of opposite spins, hold significant promise in magnonics, offering higher operating frequencies and resistance to stray fields [5][6][7][8][9][10][11] . The dual-handedness inherent in antiferromagnetic magnonics [5][6][7][8] stands in contrast to the inherently right-handed nature of ferromagnets 12,13 .…”

“…Recent observations of distinct spin wave handedness within the gigahertz regime have reported 5 Antiferromagnets, distinguished from ferromagnets by an alternating ordering of opposite spins, hold significant promise in magnonics, offering higher operating frequencies and resistance to stray fields [5][6][7][8][9][10][11] . The dual-handedness inherent in antiferromagnetic magnonics [5][6][7][8] stands in contrast to the inherently right-handed nature of ferromagnets 12,13 . The dual-handed characteristic of antiferromagnetic magnons has recently attracted attention, especially for its potential to offer novel functionalities in spintronics devices.…”