posted on 2024-02-21, 17:17authored byMatthias Küß, Stephan Glamsch, Andreas Hörner, Manfred Albrecht
The coupling between
surface acoustic waves (SAWs) and
spin waves
(SWs) in piezoelectric/magnetic heterostructures holds potential for
the realization of novel microwave devices. Since SAWs are inherently
reciprocal, the nonreciprocity arising from magnetoacoustic interaction
is of particular interest. Large nonreciprocal SAW transmission in
a limited frequency range near the intersection point of the SAW and
SW dispersions has been recently reported in several studies. Here,
we demonstrate that the nonreciprocal SW dispersion of a CoFeB(16
nm)/Ru(0.55 nm)/CoFeB(14 nm) synthetic antiferromagnet (SAF) can be
adjusted to match the linear dispersion of the SAW in a wide range
of frequencies f. Therefore, the SAW transmission
is nonreciprocal for 2.8 GHz < f < 7.0 GHz
with low losses (<0.08 dB) mediated by SAW-SW interaction in the
forward direction and large attenuation (>5 dB) in the reverse
direction.
These results hold great potential for the realization of devices
allowing wide-band nonreciprocal signal transmission.