TY - JOUR
T1 - Effect of laser induced orbital momentum on magnetization switching
AU - Kundu, A.
AU - Zhang, S.
N1 - Funding Information:
Using the time-dependent quantum perturbation theory for generic itinerant bands, we explicitly calculate the orbital momentum of itinerant electrons induced by circularly polarized light. The magnitude of the induced orbital momentum is not sufficiently large to switch the magnetization in a single laser application. It is possible to achieve magnetization switching through domain wall nucleation and propagation by repeated applications of the laser pulses. Our result is consistent with the experimental observation. This work was supported by NSF (ECCS-1404542).
Funding Information:
Using the time-dependent quantum perturbation theory for generic itinerant bands, we explicitly calculate the orbital momentum of itinerant electrons induced by circularly polarized light. The magnitude of the induced orbital momentum is not sufficiently large to switch the magnetization in a single laser application. It is possible to achieve magnetization switching through domain wall nucleation and propagation by repeated applications of the laser pulses. Our result is consistent with the experimental observation. This work was supported by NSF ( ECCS-1404542 ).
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/5/15
Y1 - 2018/5/15
N2 - The observed magnetization switching by circularly polarized ultrafast laser pulses has been attributed to the inverse Faraday effect in which the induced non-equilibrium orbital momentum serves as an effective magnetic field via spin-orbit coupling for magnetization rotation and switching. We critically examine this scenario by explicitly calculating the magnitude of the induced orbital momentum for generic itinerant band. We show that the calculated induced angular momentum is not large enough for reversing the magnetization by one laser pulse with the order of 100 femtosecond duration. Instead, we propose that each laser pulse is capable to expand a reverse domain a few nano-meters and it takes multiple pulses to complete the magnetization reversal process via domain wall motion.
AB - The observed magnetization switching by circularly polarized ultrafast laser pulses has been attributed to the inverse Faraday effect in which the induced non-equilibrium orbital momentum serves as an effective magnetic field via spin-orbit coupling for magnetization rotation and switching. We critically examine this scenario by explicitly calculating the magnitude of the induced orbital momentum for generic itinerant band. We show that the calculated induced angular momentum is not large enough for reversing the magnetization by one laser pulse with the order of 100 femtosecond duration. Instead, we propose that each laser pulse is capable to expand a reverse domain a few nano-meters and it takes multiple pulses to complete the magnetization reversal process via domain wall motion.
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U2 - 10.1016/j.jmmm.2018.01.080
DO - 10.1016/j.jmmm.2018.01.080
M3 - Article
AN - SCOPUS:85041458152
VL - 454
SP - 165
EP - 169
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
SN - 0304-8853
ER -