Picosecond Creation of Switchable Optomagnets from a Polar Antiferromagnet with Giant Photoinduced Kerr Rotations
Journal
Physical Review X
Journal Volume
9
Journal Issue
3
Date Issued
2019
Author(s)
Sheu Y.M., Chang Y.M., Chang C.P., Li Y.H., Babu K.R., Guo G.Y., Kurumaji T., Tokura Y.
Abstract
On-demand spin orientation with a long polarized lifetime and an easily detectable signal is the ultimate goal for spintronics. However, there still exists a trade-off between controllability and stability of spin polarization, awaiting a significant breakthrough. Here, we demonstrate switchable optomagnet effects in (Fe1-xZnx)2Mo3O8, from which we can obtain tunable magnetization (spanning from-40% to 40% of a saturated magnetization) that is created from zero magnetization in the antiferromagnetic state without magnetic fields. It is accomplishable by utilizing circularly polarized laser pulses to excite spin-flip transitions in polar antiferromagnets that have no spin canting, traditionally hard to control without very strong magnetic fields. The spin controllability in (Fe1-xZnx)2Mo3O8 originates from its polar structure that breaks the crystal inversion symmetry, allowing distinct on-site d-d transitions for selective spin flip. By chemical doping, we exploit the phase competition between antiferromagnetic and ferrimagnetic states to enhance and stabilize the optomagnet effects, which result in long-lived photoinduced Kerr rotations. The present study creating switchable giant optomagnet effects in polar antiferromagnets sketches a new blueprint for the function of antiferromagnetic spintronics. ? 2019 authors. Published by the American Physical Society.
Subjects
Antiferromagnetic materials; Antiferromagnetism; Economic and social effects; Magnetic fields; Magnetization; Spin polarization; Antiferromagnetic state; Antiferromagnetics; Circularly polarized laser pulse; Ferrimagnetic state; Inversion symmetry; Saturated magnetization; Spin flip transitions; Strong magnetic fields; Crystal symmetry
Other Subjects
Antiferromagnetic materials; Antiferromagnetism; Economic and social effects; Magnetic fields; Magnetization; Spin polarization; Antiferromagnetic state; Antiferromagnetics; Circularly polarized laser pulse; Ferrimagnetic state; Inversion symmetry; Saturated magnetization; Spin flip transitions; Strong magnetic fields; Crystal symmetry
Type
journal article