Here we present the tetragonal stoichiometric Heusler compound Pt2MnGa with the noncollinear AFM order stable up to 350 K. It is resolved by the neutron diffraction as a helical spiral propagating along the tetragonal axis. Ab-initio calculations suggest a pure exchange origin of the spiral and explain its helical character being stabilized by a large basal plane magnetocrystalline anisotropy (MCA). Together with the inversion-symmetric crystal structure, this provides a bi-stability of a spiral with respect to the right- and left-handed magnetic helices. Despite the large MCA, the long period of a helix might greatly facilitate the switch of the helicity by the precessional reorientation, suggesting Pt2MnGa as a potential candidate for the vector-helicity based non-volatile magnetic memory.
@article{arxiv.1604.07137,
title = {Room temperature tetragonal noncollinear antiferromagnet Pt$_2$MnGa},
author = {S. Singh and S. W. D'Souza and E. Suard and L. Chapon and A. Senyshyn and V. Petricek and Y. Skourski and M. Nicklas and C. Felser and S. Chadov},
journal= {arXiv preprint arXiv:1604.07137},
year = {2016}
}