Description du sujet de thèse

Exploring altermagnetic materials: from epitaxial growth to characterizations

Contexte de travail

Recently, a third type of magnetic materials, dubbed altermagnets, have been discovered in collinear antiferromagnets [1]. The specific symmetry of their spin structure gives rise to outstanding properties, gathering the advantages of ferromagnets (spin splitting - though highly anisotropic in momentum space-, finite anomalous magnetotransport and magnetooptical effects) and antiferromagnetic materials (vanishing magnetization by symmetry, ultrafast dynamics). The distinctive band structures of altermagnets makes it possible to expand core spin physics with altermagnets (giant or tunneling magnetoresistance effect for instance) and open up prospects for novel and interesting phenomena such as spin-splitter effect. However, these theoretical predictions still require experimental demonstration. This is partly due to the scarcity of experimentally available materials. In this context, the ALTEROSPIN project aims at developing an altermagnetic material platform to uncover their peculiar properties and unlock their potential. We will particularly explore (i) the existence of spin-polarized currents and magnons, permitting to electrically harvest antiferromagnetic properties (reliable storage of information, ultra-fast dynamics), and (ii) switchable spin-textures encoding information in altermagnetic Néel domains.
The work will be carried out within the SPIXY team at CINaM which has pioneered the epitaxial growth of one of 5 altermagnetic materials (Mn5Si3) barely one year after the first predictions of altermagnet and also explored the growth of other one. Using molecular beam epitaxy (MBE), the candidate will have in charge the growth of dedicated heterostructures to experimentally demonstrate such effects. She/he will conduct their advanced structural, chemical and magnetic characterizations. Synchrotron experiments (such as ARPES, XMCD…) may be considered. To optimize material properties and heterostructure design, the candidate will work closely with other teams in the consortium (LAF, SPINTEC, IRAMIS, LC2 and C2N) in charge of the study of their transport and magneto-optical properties and of their spin textures and associated dynamics. This complete picture will allow to unveil the underlying physical mechanisms of altermagnetic-based spintronics.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

Chemical hazards during substrate preparation
Screen work