A series of Sr(Co1−xNix)2As2 single crystals was synthesized allowing a comprehensive phase diagram with respect to field, temperature, and chemical substitution to be established. Our neutron diffraction experiments revealed a helimagnetic order with magnetic moments ferromagnetically (FM) aligned in the ab plane and a helimagnetic wavevector of q=(0,0,0.56) for x = 0.1. The combination of neutron diffraction and angle-resolved photoemission spectroscopy (ARPES) measurements show that the tuning of a flat band with dx2−y2 orbital character drives the helimagnetism and indicates the possibility of a quantum order-by-disorder mechanism.
@article{arxiv.1907.09342,
title = {Flat band magnetism and helical magnetic order in Ni-doped SrCo$_2$As$_2$},
author = {Yu Li and Zhonghao Liu and Zhuang Xu and Yu Song and Yaobo Huang and Dawei Shen and Ni Ma and Ang Li and Songxue Chi and Matthias Frontzek and Huibo Cao and Qingzhen Huang and Weiyi Wang and Yaofeng Xie and Yan Rong and David P. Young and J. F. DiTusa and Pengcheng Dai},
journal= {arXiv preprint arXiv:1907.09342},
year = {2019}
}
Comments
9 pages, 12 figures, Supplementary Material available upon request, accepted by Phys. Rev. B