Nonthermal pathway to antiferromagnetic Weyl semimetals in pyrochlore iridates*

The 227 pyrochlore iridates were conjectured to exhibit an antiferromagnetically ordered Weyl semimetallic (AF-WSM) phase provided that one could tune the ordered magnetic moment. Although the equilibrium phase diagram is still under lively debate both theoretically and experimentally, no convincing evidence has been presented for the AF-WSM, and it appears that all the known compounds are antiferromagnetic insulators (AFI). Here we propose an ultrafast nonthermal pathway to engineer a nonequilibrium AF-WSM phase with short laser pulses. Motivated by Floquet-Weyl semimetallic states in non-magnetic 3D Dirac materials [1], we investigate the dynamics after an interaction quench in a mean-field dynamics simulation starting from the AFI phase. We find nonthermal magnetic phases with Weyl fermions that emerge on femtosecond time scales. Possible experimental setups to realize our proposed scheme are discussed.
[1] H. Huebener et al., Nature Communications 8,13940 (2017).