Terahertz harmonic generation across the Mott insulator-metal transition
This study demonstrates distinct mechanisms driving terahertz harmonic generation across the Mott insulator-metal transition in rare-earth nickelates, revealing that strong spin-charge couplings, renormalized quasi-particle currents, and Mott gap-induced carrier density reduction dominate in the antiferromagnetic insulating, paramagnetic metallic, and paramagnetic insulating phases, respectively.