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March Meeting 2010. Huanlong Liu. Femtosecond magnetization dynamics using the inverse Faraday effect. THEO RASING, Radboud University Nijmegen A33.4. Background and experiment techniques. Photon polarization interacts with magnetization Sample: 20 nm GdFeCo film 40 fs laser pulse
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March Meeting 2010 Huanlong Liu
Femtosecond magnetization dynamics using the inverse Faraday effect THEO RASING, Radboud University Nijmegen A33.4
Background and experiment techniques • Photon polarization interacts with magnetization • Sample: 20 nm GdFeCo film • 40 fs laser pulse • Circular polarized: can write to film • Linear polarized: cannot write to film – use to read
Results • Laser stay at the same position: • Laser move fast:
Evolution of the domains • Using σ+: • Using σ-: Same state Initial Driving Motion Laser pulsing 0.1 ps 0 380 ps time
Magnetoresistance in magnetic nanostructures: the role of nonumiform current TATIANA RAPPOPORT [1] et. Al [1]: Universidade Federal do Rio de Janeiro H36.3 Resistance Network 500 nm Py R2 R1 Vertex: attract current Anti – vertex: attract or repel current 10 nm thickness
Mechanisms of spin torque driven ballistic precessional switching OUKJAE LEE et al, Cornell University J37.7
Sample and results • Tri-layer sample: • Switching time: • Due to dipole interaction: IAP->P > IP->AP sp Py 20 nm Py 5 nm Co 0.1 ns 0.3 ns 1 ns t
Electrical Pulse Modification and Reversal of the exchange-Bias in Magnetic Tunnel Junction Structures YUN LI et al Cornell University J37. 10
Temperature ~ exchange-bias T > TN T < TN • Normal • AF R R H H FM FM Normal AF
Switching Method • Heat up… heat current R R R Hex Tunnel barrier: Fe60Co20B20: 3nm MgO: 1.2 ~ 1.8 nm Fe60Co20B20: 3nm H H H Pulse Amplitude
Dynamic spin valve SEZEN DEMIRTAS et al, University of Texas V36.2