Magnetic ground states with peculiar spin textures, such as magnetic skyrmions and multifunctional domains are of enormous interest for the fundamental physics governing their origin as well as potential applications in emerging technologies. Of particular interest are multiferroics, where sophisticated interactions between electric and magnetic phenomena can be used to tailor several functionalities. We report the direct observation of a magnetic field induced long-wavelength spin spiral modulation in the chiral compound Ba3TaFe3Si2O14, which emerges out of a helical ground state, and is hallmarked by the onset of a unique chirality dependent contribution to the bulk electric polarization. The periodicity of the field-induced modulation, several hundreds of nm depending on the field value, is comparable to the length scales of mesoscopic topological defects such as skyrmions, merons, and solitons. The phase transition and observed threshold behavior are consistent with a phenomenology based on the allowed Lifshitz invariants for the chiral symmetry of langasite, which intriguingly contain all the essential ingredients for the realization of topologically stable antiferromagnetic skyrmions. Our findings open up new directions to explore topological correlations of antiferromagnetic spintronic systems based on non-collinear magnetic systems with additional ferroic functionalities.
Contact
Dr. Urs Staub
Staff Scientist
PSI, Photon Science Division
Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
Telephone: +41 56 310 4494
E-mail: urs.staub@psi.ch
Original Publication
Field-Induced Double Spin Spiral in a Frustrated Chiral Magnet
Mahesh Ramakrishnan, Evan Constable, Andres Cano, Maxim Mostovoy, Jonathan S. White, Namrata Gurung, Enrico Schierle, Sophie de Brion, Claire V. Colin, Frederic Gay, Pascal Lejay, Eric Ressouche, Eugen Weschk, Valerio Scagnoli, Rafik Ballou, Virginie Simonet, and Urs Staub
npj Quantum Materials 4, 60 (2019)
DOI: 10.1038/s41535-019-0199-3 (link is external)