Electrical Signal Generation at Magnetic Resonance in Insulating Antiferromagnets

Antiferromagnetic materials, particularly antiferromagnetic insulators provide an alternative to present ferromagnetic spin-transfer torque based devices which suffer from limitations in terms of density and speed owing to their magnetic anisotropy dominated spin dynamics. In antiferromagnets spin dynamics are governed by the interatomic exchange interaction energies which are orders of magnitude larger than the magnetic anisotropy energy, leading to the potential for ultrafast information processing and communication in the THz frequency range. We will present studies of spin pumping at Manganese Difluoride(MnF₂) / Platinum (Pt) interfaces at temperatures below the MnF₂ Néel temperature (T_N = 67.34K). In particular, measurements of the inverse spin Hall Effect (ISHE) voltage arising from the interconversion of the dynamically injected spin currents into Pt will be reported. We observe clear electrostatic potential signals coinciding with the MnF₂ magnetic resonance positions including the spin-flop transition (H_SF = 9T). The signals reverse by switching the polarity of the magnetic field, and display a marked dependence on the power of the microwave stimuli, as expected from the ISHE.