Magnetic field-controlled THz modulation in uniaxial anisotropic spin-valves emitters

Abstract Uniaxial spintronic heterostructures constitute compact terahertz (THz) emitters under femtosecond optical excitation, with emission amplitude and polarization governed by the applied magnetic field, are here demonstrated. We demonstrate efficient magnetically tunable THz amplitude control in ultrathin, exchange-biased Co/Pt/Co/IrMn spin-valve. THz spintronic magnetometry resolves reversible switching between parallel and antiparallel magnetization states and correlates the high- and low-emission regimes with constructive and destructive interference of charge transients generated by the inverse spin Hall effect (ISHE) in the Pt spacer. A residual low-emission signal is traced to spin-to-charge conversion in IrMn. Phase inversion under front- versus back-side excitation confirms the ISHE origin of the emission, while a macrospin Landau–Lifshitz–Gilbert model reproduces the field dependence of its amplitude and separates layer-specific contributions. Together, these results define a wafer-compatible spin-valve device architecture that enables efficient, low-field THz amplitude control.