1 Th The European Sc School l on Magnetis ism 2017 Con ondensed Matter Mag agnetis ism: Bul ulk mee eets Nano ESM2017, Introduction, Cargèse
2 PRACTICAL IN INFORMATION • Tap water is perfectly drinkable and healthy • Take a light with you if you walk from IESC to village in the dark • Survival kit of French language in the booklet • Wifi available at IESC. Please use it for learning purposes during the lectures ESM2017, Introduction, Cargèse
4 HISTORY of f th the SCHOOL Start: French-Romanian schools Grenoble / Cluj-Napoca 11 th school since 1997 • Nanomagnetism (1997) Oradea • High performance permanent magnets (1999) Cluj-Napoca • Spectroscopic analysis (2001) Cluj • Magnetism of nanoscopic systems and hybrid structures (2003) Brasov • New experimental approaches in magnetism (2005) Constanta • New Magnetic Materials and their Functions (2007) Cluj • Models in magnetism: from basic aspects to practical uses (2009) Timisoara • Time-dependent phenomena in magnetism (2011) T ã rgovi s̨ te • Magnetism for Energy (2013) Cargèse • From basic concepts to spin currents (2015) Cluj • Condensed Matter Magneti tism: bulk lk mee eets nano (2017 2017) Ca Cargèse • Magnetism by light (2018) Kraków • Experimental techniques (2019) Brno • … (2020) Saarbrück ESM2017, Introduction, Cargèse
5 An or organization to promote magnetis ism in in Europe Mission Actions Advance knowled edge ESM Hig Higher ed education Conference: JE Con JEMS Promote applic licati tions, lin link academic ics Netw tworkin ing th through th the e web eb sit ite: e: and in industry ry News Rep epresen entation of of th the e magnetics Job Job market com ommunity (E (European Physic ical Agen enda of of even ents ts Soc ocie iety, polic olicy makers etc. c.) Lin Links (s (soc ocieti ties, too ools ls, book ooks, com ompanies) Web site: http://magnetism.eu ESM2017, Introduction, Cargèse
6 Web site: http://magnetism.eu/jems ESM2017, Introduction, Cargèse
7 WHAT is is ESM ? Objectives Key facts Modern education on the foundations La Large : 85 students of Magnetism Lon Long : 11 full days • Basic lectures (50%) Br Broa oad sc scope ; mix communities • Specialized lectures (50%) Affordable for or all all : Networking low cost; a few grants offered • Student ↔ Student ↔ Lecturer Tim iming: every 2 years (so far), • Student ↔ Industrial will change to every year starting 2018 ESM2017, Introduction, Cargèse
8 About ESM 2017 Organizing committee : Olivier Fruchart, Virginie Simonet, Olivier Isnard, Claudine Lacroix, Ingrid Mertig, Muriel Martinez (secretary SFP) Local student committee : Vadim Cathelin, Elie Ravoavy, Titiksha Srivasta, Beatrix Trapp, Dominika Zákutná Scientific Advisory Committee : Franca Albertini, Stephen Blundell, Michael Coey, Vincent Cros, Alina Deac, Claudia Felser, Olivier Fruchart, Laura Heyderman, Olivier Isnard, Andrei Kirilyuk, Claudine Lacroix, Christian Pfleiderer, Marek Przybylski, Karl Sandeman, Virginie Simonet, Nicola Spaldin, Josef Spałek , Julie Staunton, Sergio O. Valenzuela, Wulf Wulfhekel, Andrej Zorko Location ESM2017, Introduction, Cargèse
9 Su Support ESM2017, Introduction, Cargèse
10 YOU ! 235 requests, 85 participants, 30 % ladies Labs from 41 countries • Mainly Europe • 10 % Asia, Middle-East, Americas Almost 2/3 rejection rate ESM2017, Introduction, Cargèse
11 Motivations for 2017 topics Two main communities, Bulk and Nano , working in the field of magnetism Different : aims, tools, materials, BUT: Recent convergence around some topics : spin-orbit coupling, topological matter, magnetic chirality, skyrmions, oxitronics, multiferroics, magnetic, excitations … Aim: Foster cross-fertilization . Prepare the next generation of researchers in magnetism with a foot in each field! ESM2017, Introduction, Cargèse
12 Motivations for 2017 topics: the bulk side - Find new behaviors at the origin of concepts/models spreadable in other fields - Microscopic mechanisms and unconventional behaviors of complex materials. Extreme conditions Dedicated tools : Several degrees of freedom (lattice, - Macroscopic measurements spin, orbit, charge, … ) - Local probes: NMR, muSR, ESR … Complex bulk materials - Spectroscopy (Raman, optics, THz) Competing effects - Neutron and X ray diffraction − − − − − Calculation − − − − -> work in reciprocal space Energy [meV] 3 Topics : Multiferroics/magnetoelectrics; Excitations (spinwaves, − ] in 1.2001 Å − − ` [0 -1 ] fractional); Topological magnetism; Spin-orbit coupling; Chirality, skyrmions, spin textures; Magnetic frustration; Quantum magnetism, low dimensionality ESM2017, Introduction, Cargèse
13 Motivations for 2017 topics: the Nano side -New functionalities associated with nanoscale and interfaces -High potential of nanomagnetic systems for present and future technologies ’ é Aiming at room temperature Topics : Simple materials, designed at the Spintronics nanoscale or in heterostructures High magnetoresistance / Spin transfer Tools: microscopy, micromagnetic Magnetization dynamics, Magnonics calculations, X-ray dichroism Novel way to control magnetism Physics + applications Skyrmionics Oxytronics, antiferromagnetic spintronics ’ é ’ ê ’é ure né ure Giant magnetoresistance Fert, Gr ü nberg, et al. 1988 ESM2017, Introduction, Cargèse
14 Motivations for 2017 topics. Example: frustration Magnetic frustration : one or several constrains can not be satisfied simultaneously gné pé ê né Through competing interactions: Through the geometry of the lattice : Spin chain ≠ Degeneracy Ising éomé (measured by AFM J 1 à finite entropy) ≈ AFM J 2 ôté ? gné Complex magnetic order é ? ESM2017, Introduction, Cargèse
15 Motivations for 2017 topics. Example: frustration Bulk Nano Exotic fluctuating states and excitations : Artificial spin ice Spin liquids, spin ices (magnetic monopole) Nanomagnetic = macrospin) Coulomb phases, … Designed at will, models can be tested water ice Neutron diffuse scattering Pyrochlore lattice ESM2017, Introduction, Cargèse
16 Motivations for 2017 topics. Example: multiferroism C oexistence of at least two (anti)ferroic orders among : ferroelasticity, ferromagnetism, ferroelectricity, and ferrotoroidicity + Hysteresis cycle , presence of switchable domains Possible coupling between order parameters Van Aken et al. Nature 449 (2007) d ’ apr è s [Van Aken et al. Nature 449 (2007) 702] ESM2017, Introduction, Cargèse
17 Motivations for 2017 topics. Example: multiferroism Bulk Nano Complex (H,T) phase diagram Use interfaces instead of compounds Complex magnetic structures (ex. cycloids) Ferroelectricity can be induced by magnetism Strong Magnetoelectric coupling Ni 3 V 2 O 8 Lawes PRL 2005 ESM2017, Introduction, Cargèse
18 Motivations for 2017 topics. Example: chirality D istinguishes a phenomenon from its counterpart in a mirror (or inversion center) Χειρ Hand in Greek ESM2017, Introduction, Cargèse
19 Motivations for 2017 topics. Example: chirality Extended definition of chirality in Magnetism Sense of rotation of non collinear Bloch, Néel, V gné spins along an orientated line pé ê né ≠ éomé à Spinwaves ôté Domain walls gné Chiralit é Magnetic helix Triangular chirality Skyrmions ESM2017, Introduction, Cargèse
20 Motivations for 2017 topics. Example: chirality Skyrmions in bulk Skyrmions in nano MnSi FeCoSi Physics Experiments Small Angle Neutron Scattering Reciprocal space Devices ? Non-centrosym MnSi, FeGe, FeCoSi metals, and Cu 2 OSeO 3 insulator Skyrmion hexagonal lattice S. Heinze et al . Nat. Phys. 2011, N. Romming, Science (2013) Mühlbauer et al . Science 2009 Fert et al . Nat. Nanotech. 2013 Yu et al . Nature 2010 Seki et al . Science 2012 ESM2017, Introduction, Cargèse
21 Motivations for 2017 topics. Example: spin-orbit coupling Coupling between spin and orbital angular momenta, short-range relativistic effect between first neighbors. Strongest for heavier atoms like Ir, Pt transition metals (“heavy metals”) exhibit str 3 d ferromagnets 5 d heavy metals ESM2017, Introduction, Cargèse
22 Motivations for 2017 topics. Example: spin-orbit coupling Bulk Nano Multilayers with heavy atoms (Pt, Ir, Ta) Recent interest in iridates Strong Dzyaloshinskii-Moryia Prediction of a novel entangled interactions-> skyrmions & chiral walls spin-orbital state J eff =1/2 Rashba effect, spin-orbit torque, Hall effect -> magnetization manipulation & reading of spin currents Consequences: Spin-orbit driven Mott insulator Topological phases New anisotropy of magnetic interactions leading to novel ground states (ex. Kitaev spin liquid) and Enhanced-efficiency conversion effects for excitations (ex. Majorana fermions) spintronic applications ESM2017, Introduction, Cargèse
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