magnetoelectric coupling; magnetoelectric dynamics; artificial multiferroics; x-ray spectroscopy
Luo Zhaochu, Dao Trong Phuong, Hrabec Aleš, Vijayakumar Jaianth, Kleibert Armin, Baumgartner Manuel, Kirk Eugenie, Cui Jizhai, Savchenko Tatiana, Krishnaswamy Gunasheel, Heyderman Laura J., Gambardella Pietro (2019), Chirally coupled nanomagnets, in Science
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Vijayakumar Jaianth, Bracher David, Savchenko Tatiana M., Horisberger Michael, Nolting Frithjof, Vaz C. A. F. (2019), Electric field control of magnetism in Si 3 N 4 gated Pt/Co/Pt heterostructures, in Journal of Applied Physics
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Mendil J., Trassin M., Bu Q., Schaab J., Baumgartner M., Murer C., Dao P. T., Vijayakumar J., Bracher D., Bouillet C., Vaz C. A. F., Fiebig M., Gambardella P. (2019), Magnetic properties and domain structure of ultrathin yttrium iron garnet/Pt bilayers, in Physical Review Materials
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Arava Hanu, Derlet Peter M, Vijayakumar Jaianth, Cui Jizhai, Bingham Nicholas S, Kleibert Armin, Heyderman Laura J (2018), Computational logic with square rings of nanomagnets, in Nanotechnology
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Avula S. R. V., Heidler J., Dreiser J., Vijayakumar J., Howald L., Nolting F., Piamonteze C. (2018), Study of magneto-electric coupling between ultra-thin Fe films and PMN-PT using X-ray magnetic circular dichroism, in Journal of Applied Physics
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The current need for advanced materials with enhanced functionalities has been the driving force for much research in novel materials and artificial heterostructures. A prominent example is that provided by multiferroic materials, which are characterised by the simultaneous presence of, and a coupling between, magnetic and ferroelectric orders. Such functionality could enable the electric field control of magnetism or the magnetic generation of electromotive forces in the solid state, features that have a strong potential for device applications and which is a key motivation behind the current interest in these materials systems. In this proposal, we aim to investigate the time response of the magnetoelectric coupling in artificial multiferroic heterostructures based on complex oxides, with emphasis on the magnetic response of the system to fast electric excitations in the relevant time scale from 1-1000 ps. The magnetic response will be measured in a pump-probe manner using time-resolved magneto-optic Kerr effect and spatially-resolved advanced synchrotron x-ray spectroscopy techniques, which have intrinsic time resolutions of the order of 100 fs and 100 ps, respectively, and spatial resolutions down to 15 nm. By probing the magnetoelectric time response of charge-mediated artificial multiferroics with x-ray spectroscopy, we expect to learn which electronic mechanisms are responsible for the coupling between charge and spin at the interface and how such mechanisms operate in the time and space domain. This research work is made possible by a unique combination of characterisation tools only available at the Swiss Light Source and will pioneer fast switching magnetoelectric dynamics in multiferroic materials. It will have the merit of benchmarking the time response of such systems, which is critical for device applications.