Nobelovac Albert Fert (NXPowerLite)

Slide1: 

Zagreb, May 2008, A. Fert, CNRS/Thales, Palaiseau, and Université Paris-Sud In classical spintronics: new types of MTJ The present and future of Spintronics Tulapurkar et al Hruska et al

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Introduction : Spin dependent conduction in ferromagnetic conductors, Giant Magnetoresistance (GMR), Tunnel Magnetoresistance (TMR)

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 = /

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Spin Transfer (magnetic switching, microwave generation) Spintronics with semiconductors Spintronics with molecules

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Spin transfer (J. Slonczewski, JMMM 1996, L. Berger, PR B 1996)

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Py = permalloy

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Spintronics with semiconductors and molecules

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GaMnAs (Tc170K) and R.T. FS Electrical control of ferromagnetism TMR, TAMR, spin transfer (GaMnAs) Field-induced metal/insulator transition Spintronics with semiconductors Magnetic metal/semiconductor hybrid structures Example: spin injection from Fe into LED (Mostnyi et al, PR. B 68, 2003) Ferromagnetic semiconductors (FS)

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Nonmagnetic lateral channel between spin-polarized source and drain Semiconductor channel: « Measured effects of the order of 0.1-1% have been reported for the change in voltage or resistance (between P and AP)…. », from the review article « Electrical Spin Injection and Transport in Semiconductors » by BT Jonker and ME Flatté in Nanomagnetism (ed.: DL Mills and JAC Bland, Elsevier 2006)

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Window only for lsf(N) > L

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Quasi-continuous DOS, same conditions as for semiconductor or metallic channel Uc=e2/2C eV  1 meV Usual conditions: small bias voltage experiments LSMO/CNT/LSMO: higher voltage experiments thanks to large interface resistances and small V2/R heating at large V Oscillatory variation of the conductance, different signs of theMR depending on the bias voltage and from sample to sample

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from Jaffrès and A.F. (see also Yu and Flatté)

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Diffusive transport Ballistic transport + additional geometrical parameters when the number of conduction channels is different for the injection and in the channel (W  w in the example)