SPIN-WAVE ARCHITECTURES - Bio-Inspired and Nanoscale Integrated Computing - page 217

7.8. EXPERIMENTAL RESULTS

In Figure 7.14, we have schematically shown the prototype of the spin-wave logic
device structure. The core of the structure consists of a 100 nm-thick CoFe film
deposited on a silicon substrate. There are two asymmetric co-planar strip (ACPS)
transmission lines on the top of the structure. The distance between the lines is
8 m m. The lines and the ferromagnetic layer are isolated by a 300 nm silicon oxide
layer. The dimensions of the ACPS lines are adjusted to match 50 O of the external
coaxial cable. One of the ACPS lines (shown on the right) is used for spin-wave
excitation. Hereafter, we will refer to this ACPS line as the ''excitation'' line.
A voltage pulse applied to the excitation line produces a magnetic field and excites
a spin wave (spin-wave packet) in the ferromagnetic layer. Being excited, the spin-
wave propagates through the ferromagnetic film. The other ACPS line (shown on
the left) is used to detect the inductive voltage signal produced by the propagating
spin wave. Hereafter, we will refer to this line as the ''detection'' line.
Figure 7.15 shows the experiment setup, where an input voltage pulse with an
amplitude of 24.5 V, rising time of 1.2 ns, and pulse length of 20 ns is applied to the

ACPS line

ACPS line

Z

Y 8 m

X

SiO 2

Ferromagnetic film 100 nm

(CoFe)

S.I. substrate

(a)

ACPS line
to detect spin

ACPS line
to excite spin wave

Z

Y

SiO 2

X

Spine wave

Ferromagnetic film

S.I. substrate

(b)

Figure 7.14. Prototype of spin-wave device used in the experiments.