Attempting nanolocalization of all-optical switching through nano-holes in an Al-mask

We investigate the light-induced magnetization reversal in samples of rare-earth transition metal alloys, where we aim to spatially confine the switched region at the nanoscale, with the help of nano-holes in an Al-mask covering the sample. First of all, an optimum multilayer structure is designed for the optimum absorption of the incident light. Next, using finite difference time domain simulations we investigate light penetration through nano-holes of different diameter. We find that the holes of 200 nm diameter combine an optimum transmittance with a localization better than λ/4. Further, we have manufactured samples with the help of focused ion beam milling of Al-capped TbCoFe layers. Finally, employing magnetization-sensitive X-ray holography techniques, we have investigated the magnetization reversal with extremely high resolution. The results show severe processing effects on the switching characteristics of the magnetic layers.

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

[2]  S. Moussaoui,et al.  Demonstration of laser induced magnetization reversal in GdFeCo nanostructures , 2012 .

[3]  Catherine Graves,et al.  Femtosecond single-shot imaging of nanoscale ferromagnetic order in Co/Pd multilayers using resonant x-ray holography. , 2012, Physical review letters.

[4]  W. Schlotter,et al.  Nanoscale spin reversal by non-local angular momentum transfer following ultrafast laser excitation in ferrimagnetic GdFeCo. , 2013, Nature materials.

[5]  Duane C. Karns,et al.  Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer , 2009 .

[6]  JAMES STUART,et al.  Magnetism , 1872, Nature.

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

[8]  Manuel Guizar-Sicairos,et al.  Holography with extended reference by autocorrelation linear differential operation. , 2007, Optics express.

[9]  J. Fienup,et al.  High-resolution X-ray lensless imaging by differential holographic encoding. , 2009, Physical review letters.

[10]  A. Khorsand,et al.  Highly efficient all-optical switching of magnetization in GdFeCo microstructures by interference-enhanced absorption of light , 2012 .

[11]  Teri W Odom,et al.  Direct evidence for surface plasmon-mediated enhanced light transmission through metallic nanohole arrays. , 2006, Nano letters.

[12]  T. Rasing,et al.  Optical energy optimization at the nanoscale by near-field interference , 2012, 1211.3532.

[13]  S. Moussaoui,et al.  Ultrafast heating as a sufficient stimulus for magnetization reversal in a ferrimagnet , 2012, Nature Communications.

[14]  B. Hecht,et al.  Principles of nano-optics , 2006 .

[15]  A. Khorsand,et al.  Optical excitation of thin magnetic layers in multilayer structures. , 2014, Nature materials.

[16]  Jordan A. Katine,et al.  Magnetic recording at 1.5 Pb m −2 using an integrated plasmonic antenna , 2010 .

[17]  Marco Finazzi,et al.  Ultrafast generation of nanostructures with tunable topological properties by single laser pulse illumination , 2013, Optics & Photonics - NanoScience + Engineering.

[18]  M. Katsnelson,et al.  Non-equilibrium magnetic interactions in strongly correlated systems , 2012, 1212.3671.

[19]  Eric E. Fullerton,et al.  Magnetic recording: advancing into the future , 2002 .

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

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

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

[23]  A. Khorsand,et al.  Laser-induced magnetic nanostructures with tunable topological properties. , 2013, Physical review letters.

[24]  H. Lezec,et al.  Extraordinary optical transmission through sub-wavelength hole arrays , 1998, Nature.

[25]  A. Khorsand,et al.  Role of magnetic circular dichroism in all-optical magnetic recording. , 2012, Physical review letters.

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

[27]  David Jenkins,et al.  Optical and magneto-optical characterization of TbFeCo and GdFeCo thin films for high-density recording , 2003 .