Fachgruppe Nanostrukturierte Materialien    

The field of THz spintronics is a novel direction in the research field of spintronics that combines magnetism withoptical physics and ultrafast photonics. The experimental scheme of the field involves the use of femtosecondlaser pulses to trigger ultrafast spin and charge dynamics in bilayers composed of ferromagnetic (FM) and non-magnetic (NM) thin films where the NM layer features a strong spin-orbit coupling. The key technological andscientific challenges of THz spintronic emitters is to increase their intensity and frequency bandwidth. To achievethis the control of the source of the radiation, namely the transport of the ultrafast spin current is required.However, the transfer of a spin current from a FM to a NM layer is a highly interface-sensitive effect. In this workwe study the properties of the spin current transport through the interface measuring the strength of the THzemission and compare it to the effective spin mixing conductance, one of the key concepts in the spin currenttransport through interfaces. The results show an enhancement of the spin mixing conductance for interfaceswith higher degree of epitaxy similarly to the improvement of the THz emission. The proportionality betweenspin mixing conductance and THz emission can define new directions in engineering the emission of spintronicTHz emitters.