Strain-induced magnetization in collinear antiferromagnet RuO2

RuO2 is a colinear antiferromagnet with many interesting properties, including spin current generation arising from its band topology, crystal Hall effect, spin-valley locking and piezomagnetism, and Néel vector-dependent spin current generation from its band anisotropy. While the piezomagnetism, which originates in strain-lifting of the valley degeneracy, has been theoretically predicted, experimental realization has remained elusive. We find an emergent net magnetization in strained RuO2 on Al2O3 and on TiO2 and propose to investigate the origins using polarized neutron reflectometry.