Low Temperature Physics: 32, 748 (2006); https://doi.org/10.1063/1.2219497 (20 pages)
Физика Низких Температур: Том 32, Выпуск 8-9 (Август 2006), c. 985-1009    ( к оглавлению , назад )

Ultrafast all-optical control of the magnetization in magnetic dielectrics

Andrei Kirilyuk1, Alexey Kimel1, Fredrik Hansteen1, Roman V. Pisarev2, and Theo Rasing1

1IMM, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
E-mail: A.Kirilyuk@science.ru.nl

2Ioffe Physico-Technical Institute, 194021 St.-Petersburg, Russia

Received February 24, 2006

Аннотация

The purpose of this review is to summarize the recent progress on laser-induced magnetization dynamics in magnetic dielectrics. Due to the slow phonon–magnon interaction in these materials, direct thermal effects of the laser excitation can only be seen on the time scale of almost a nanosecond and thus are clearly distinguished from the ultrafast nonthermal effects. However, via the crystal field, laser pulses are shown to indirectly modify the magnetic anisotropy in rare-earth orthoferrites and lead to the spin reorientation within a few picoseconds. More interesting, however, are the direct nonthermal effects of light on spin systems. We demonstrate coherent optical control of the magnetization in ferrimagnetic garnet films on a femtosecond time scale through a combination of two different ultrafast and nonthermal photomagnetic effects and by employing multiple pump pulses. Linearly polarized laser pulses are shown to create a long-lived modification of the magnetocrystalline anisotropy via optically induced electron transfer between nonequivalent ion sites. In addition, circularly polarized pulses are shown to act as strong transient magnetic field pulses originating from the nonabsorptive inverse Faraday effect. An all-optical scheme of excitation and detection of different antiferromagnetic resonance modes with frequencies of up to 500 GHz will be discussed as well. The reported effects open new and exciting possibilities for ultrafast manipulation of spins by light, and provide new insight into the physics of magnetism on ultrafast time scales.

PACS:
78.47.+p - Time-resolved optical spectroscopies and other ultrafast optical measurements in condensed matter (see also 42.65.Re-in nonlinear optics; 82.53.-k Femtochemistry in physical chemistry and chemical physics)
78.20.Ls - Magnetooptical effects
75.30.Gw - Magnetic anisotropy
75.40.Gb - Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.)

Ключевые слова: magnetization dynamics, magnetic dielectrics, Faraday effects.