Quantum mechanics

Materials science

Ferromagnetism

Coupling (piping)

Scattering

Surface acoustic wave

Telecommunications

Computer science

Acoustics

Acoustic wave

Inductive coupling

Physics

Amplitude

Optics

Condensed matter physics

Circulator

Composite material

Transmission (telecommunications)

Applied Physics Express

We have studied the transmission of surface acoustic waves (SAWs) in ferromagnetic/non-magnetic/ferromagnetic tryilayers. The SAW scattering matrix is studied for devices with various non-magnetic spacer thickness, which defines the strength of the interlayer exchange coupling. We find the SAW transmission amplitude depends on its propagation direction when the two ferromagnetic layers are coupled antiferromagnetically. The degree of such SAW nonreciprocity increases with increasing exchange coupling strength and reaches 37 dB mm −1 for a device with the thinnest spacer layer. These results show the potential of interlayer exchange coupled synthetic antiferromagnets for viable acoustic nonreciprocal transmission devices, such as circulators and isolators.

Large surface acoustic wave nonreciprocity in synthetic antiferromagnets