@inproceedings{ca80f5a427a8440d9a003cca7b9f1c09,
title = "Oxygen-vacancy driven tunnelling spintronics across MgO",
abstract = "The conservation of an electron's spin and symmetry as it undergoes solid-state tunnelling within magnetic tunnel junctions (MTJs) is thought to be best understood using MgO-based MTJs1. Yet the very large experimental values of tunnelling magnetoresistance (TMR) that justify this perception are often associated with tunnelling barrier heights well below those suggested by the MgO optical band gap. This combination of high TMR and low RA-product, while spawning spin-transfer/spin-orbit torque experiments and considerable industrial interest, cannot be explained by standard theory. Noting the impact of a tunnel barrier's altered stoichiometry on TMR2, we reconcile this 10+year-old contradiction between theory and experiment by considering the impact of the MgO barrier's structural defects3-5. We find that the ground and excited states of oxygen vacancies can promote localized states within the band gap with differing electronic character. By setting symmetry- and temperature-dependent tunnelling barrier heights, they alter symmetry-polarized tunnelling and thus TMR. We will examine how annealing, depending on MgO growth conditions, can alter the nature of these localized states. This oxygen vacancy paradigm of inorganic tunnelling spintronics opens interesting perspectives into endowing the MTJ with additional functionalities, such as optically manipulating the MTJ's spintronic response.",
keywords = "Localized states, Magnetic tunnel junction, Oxygen vacancy, Photoluminescence, Spin transfer torque, Spintronics",
author = "U. Halisdemir and F. Schleicher and Kim, {D. J.} and B. Taudul and D. Lacour and Choi, {W. S.} and M. Gallart and S. Boukari and G. Schmerber and V. Davesne and P. Panissod and D. Halley and H. Majjad and Y. Henry and B. Leconte and A. Boulard and D. Spor and N. Beyer and C. Kieber and E. Sternitzky and O. Cregut and M. Ziegler and F. Montaigne and J. Arabski and E. Beaurepaire and W. Jo and M. Alouani and P. Gilliot and M. Hehn and M. Bowen",
note = "Funding Information: F.S. gratefully acknowledges financial support from the CNRS. We thank Y. Yin for assistance with optical experiments and S. Colis for technical assistance, the STNano technological platform for access and J. Stoll, J.-G. Faullumel, B. Muller and G. Dekyndt of the IPCMS machine shop for assistance. This work was supported by grants from the EU (EC FP6 NMP3-CT-2006-033370), the ANR (ANR-06-NANO-033-01, ANR-09-JCJC-0137, ANR-14-CE26-0009-01 and ANR-09-Blan-076), the Labex NIE (ANR-11-LABX-0058-NIE 'Symmix'), the CNRS (STII PEPS 'SpinTrans', PICS 'Oxyspin'), the University of Strasbourg, La R{\'e}gion Alsace, le FEDER and La R{\'e}gion Lorraine; and by the Korean MEST Grant No. 2010K000339 from CNMT under 21st Century Frontier R&D Programs; Grant No. NRF 2010- 0020416. Publisher Copyright: {\textcopyright} 2016 SPIE.; Spintronics IX ; Conference date: 28-08-2016 Through 01-09-2016",
year = "2016",
doi = "10.1117/12.2239017",
language = "English",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Jean-Eric Wegrowe and Henri-Jean Drouhin and Manijeh Razeghi",
booktitle = "Spintronics IX",
}