Role of magnetic circular dichroism in all-optical magnetic recording.

Using magneto-optical microscopy in combination with ellipsometry measurements, we show that all-optical switching with polarized femtosecond laser pulses in ferrimagnetic GdFeCo is subjected to a threshold fluence absorbed in the magnetic layer, independent of either the excitation wavelength or the polarization of the laser pulse. Furthermore, we present a quantitative explanation of the intensity window in which all-optical helicity-dependent switching (AO-HDS) occurs, based on magnetic circular dichroism. This explanation is consistent with all the experimental findings on AO-HDS so far, varying from single- to multiple-shot experiments. The presented results give a solid understanding of the origin of AO-HDS, and give novel insights into the physics of ultrafast, laser controlled magnetism.

[1]  T. Rasing,et al.  Femtosecond photomagnetic switching of spins in ferrimagnetic garnet films. , 2005, Physical review letters.

[2]  T. Rasing,et al.  Ultrafast optical manipulation of magnetic order , 2010 .

[3]  F. Nori,et al.  Spin oscillations in antiferromagnetic NiO triggered by circularly polarized light. , 2010, Physical review letters.

[4]  Merle,et al.  Ultrafast spin dynamics in ferromagnetic nickel. , 1996, Physical review letters.

[5]  R. London,et al.  Characteristics of focused soft X-ray free-electron laser beam determined by ablation of organic molecular solids. , 2007, Optics express.

[6]  T. Rasing,et al.  All-optical magnetic recording with circularly polarized light. , 2007, Physical review letters.

[7]  David L. Windt,et al.  IMD—software for modeling the optical properties of multilayer films , 1998 .

[8]  P. Pershan,et al.  Theoretical Discussion of the Inverse Faraday Effect, Raman Scattering, and Related Phenomena , 1966 .

[9]  Kohlhepp,et al.  Ultrafast magneto-optics in nickel: magnetism or optics? , 2000, Physical review letters.

[10]  H. Dürr,et al.  Transient ferromagnetic-like state mediating ultrafast reversal of antiferromagnetically coupled spins , 2011, Nature.

[11]  M. Katsnelson,et al.  Ultrafast spin dynamics in multisublattice magnets. , 2012, Physical review letters.

[12]  M Finazzi,et al.  Cross resonant optical antenna. , 2009, Physical review letters.

[13]  U. Nowak,et al.  Ultrafast path for optical magnetization reversal via a strongly nonequilibrium state. , 2009, Physical review letters.

[14]  Eric E. Fullerton,et al.  Nanoscale magnetic materials and applications , 2009 .

[15]  P. Biagioni,et al.  Near-field circular polarization probed by chiral polyfluorene. , 2009, Optics letters.

[16]  R. Pisarev,et al.  Ultrafast non-thermal control of magnetization by instantaneous photomagnetic pulses , 2005, Nature.

[17]  Martin Aeschlimann,et al.  All-optical magnetization recording by tailoring optical excitation parameters , 2011 .

[18]  M. Kokkoris,et al.  THE BOOK OF ABSTRACTS , 2015 .

[19]  J. Liu.  Simple technique for measurements of pulsed Gaussian-beam spot sizes. , 1982, Optics letters.

[20]  E. D. van Hattum,et al.  Single shot damage mechanism of Mo/Si multilayer optics under intense pulsed XUV-exposure. , 2010, Optics express.