Strain-induced antiferromagnetic domain switching via the spin Jahn-Teller effect

The spin Jahn-Teller effect, where a degeneracy of magnetic ground states is spontaneously lifted by structural distortions, lends itself to exploitation by the implied magnetoelastic coupling. CoTi₂O₅ hosts a frustrated topology of magnetic interactions that could realize such coupling, since the observed magnetic ground state requires a spontaneous monoclinic distortion of the crystal. Using resonant elastic x-ray scattering to simultaneously probe the magnetic structure and lattice distortion of CoTi₂O₅, we demonstrate near complete magnetic domain switching by an applied uniaxial stress that is conjugate to the monoclinic strain. Our results, supported by density functional theory calculations, confirm that CoTi₂O₅ displays spin Jahn-Teller effects that can be understood in terms of modulated Heisenberg exchange interactions, and demonstrate the potential functionality of spin Jahn-Teller materials in spintronic devices sensitive to uniaxial strain.