Andrey Grachev, Alexandr Sadovnikov, Evgeny Beginin
Saratov State University
BLOCH OSCILLATIONS AND TUNABLE SPIN-WAVE TRANSPORT IN ARRAYS OF MAGNETIC STRUCTURES
MOTIVATION
Kotel'nikov Institute of
Radio Engineering and
Electronics of
Russian Academy of
Sciences
arato
MS
agnonics
v
1Saratov State University, 410012, Saratov, Russia
532 nm
Fp2
laser
Fp1
Scan
Sample
fs fas
scattering spetra2D BLS spin-wave intensity map
YIG
Brillouin light scatteringspetroscopy(0-300 GHz)
(BLS) Demokritov S.O. et al. //
Phys. Rep. 2001. V. 348. P. 441.
EXPERIMENT
Signal generatorAnritsu
MG3692С
PNA Network Analyzer
AgilentE8352C
YIG
H = 0-1.8 T0
Microwave spetroscopy(0-67 GHz)
џ The planar microstructures based on thin ferrimagnetic films of yttrium iron garnet (YIG) opens a promising alternative to signal processing by spin waves in beyond-CMOS computing technology, based on magnonic networks with low-level energy consumption.
џ We report here on dipolar spin-wave coupling in the lateral topology of adjacent YIG stripes. We propose control of spin-wave coupling characteristics by variation of the static magnetization angle. The functionality of the proposed magnonic coupler was verified with micromagnetic simulation of spin-wave propagation along adjacent stripes. By the means of micromagnetic numerical simulation, the transmission spectra of SW were calculated. It was shown that lateral magnonic stripes can be used as a functional unit in planar magnonic networks as a directional coupler, spin-wave multiplexer, and microwave powerdivider. Using Brillouin light scattering spectroscopy we experimentally demonstrated spin-wave transport along bilateral magnonic stripes.
GGG
BLS STUDY OF SPIN-WAVE PROPAGATION
3MUMAX
SIMULATION
џ We propose control of spin-wave coupling characteristics by variation of the static magnetization angle. The functionality of the proposed magnonic coupler was verified with micromagnetic simulation of spin-wave propagation along adjacent stripes.
џ Using Brillouin light scattering spectroscopy we experimentally demonstrated spin-wave transport along bilateral magnonic stripes.
CONCLUSION
200 mm
x
probing laser light
Spin Wave
x
z
yj
Hmssw
GGG
YIGYIG
YIG
d
w
t
Hbvmsw
Pin
Pout1Pout2 Pout3
MULTI-CHANNEL DIRECTIONAL COUPLER
4pM =1750 G (saturation magnetization) 0
t=10 mm (YIG film thickness)
d = 40 mm (distance between stripes )
y
BLS intensity (arb.units)0 1
0 1.0 2.0 3.0
y-co
ordi
nate
(m
m)
4.0
x-coordinate (mm)
(a)790395
-3950
-790
0 1.0 2.0 3.0 4.0
(b)790395
-3950
-790H0
oj = -15
0 1.0 2.0 3.0 4.0
(c)790395
-3950
-790H0
oj = 15
0395790
-790-395
S1
S2
S3
(a)
Intensity (arb.units)0 1
0 1.0 2.0 3.0 4.0
y-co
ordi
nate
(m
m)
0395790
-790-395
S1
S2
S3
(b)
0 1.0 2.0 3.0 4.0x-coordinate (mm)
0395790
-790-395
S1
S2
S3
(c)
0 1.0 2.0 3.0 4.0
0395790
-790-395
S1
S2
S3
(d)
0 1.0 2.0 3.0 4.0
H0
oj=15
H0
oj=0
H0
oj=0
H0
oj = 15
φ = 0°
0 395 790-395-790
1185
1190
1195
H (
Oe)
in
t
ΔH int
φ = 15°φ = 30°
y-coordinate (mm)
DH
int
4.0
01.02.03.0
0 20 40 60 80 100 120j (deg)
DH
(O
e)in
t
y-coordinate
1180
The intensity distribution in the case of p r o p a g a t i o n o f s u r f a c e magnetostatic waves (left column) and backward-volume magnetostatic waves (right column) with rotation of the bias angle j. It can be seen that when the angle j is rotated about the x axis, a transformation of the spatial intensity distribution in the side bars S is observed, in 1,3
particular, a decrease in intensity in the stripe S . 3
2 2( , ) x zI x y m m= +
The profiles of internal magnetic field H of three coupled magnetic stripes in case int
of varying the bias angle φ. It is seen that with increasing bias angle, the magnitude of the internal magnetic field is transformed in each stripe. We introduce the parameter ΔH = H - H , which determines the difference of the internal fields in int int2 int1,3
the stripes S and S or S . 2 1 3
An experimental study of the spatial dynamics of the MSSW was carried out using the Brillouin light spectroscopy of magnetic materials. In figures (a-c) shows spatial maps of the intensity of the spin wave I BLS
with a change in the bias angle j. It can be seen that when the angle j is rotated about the y axis, a transformation of the spatial intensity distribution in the side bars S is observed, in particular, a 1,3
decrease in intensity in the stripe S . 3
F. Lederer, G.I. Stegeman, D.N. Christodoulides et al., Phys. Rep., 463, 1 26 (2008).
2+C(A +A )+γ|A | A = 0n+1 n-1 n nβAn+
dAn
dzi
β - wavenumber in single microstrip
C = π/2L( f ) - coupling between 2 stripes
γ - nonlinear parameter
A - amplitude in n-th stripen
x-co
ord
inate
, m
m
z-coordinate, mm
YIG
YIG
YIG
GGG-substrate4
3
2
0 2.0 4.0 6.0 8.0
YIG 1
YIG 0
-1
-2
-3
-4
YIG
YIG
YIG
YIG
0.0
1.0
2.0
40 m
m140 m
m
NUMERICAL MODEL
Nonlinear discrete Schrödinger equation
k =β-2C cos(k d) - dispersionz x
2∂kx
2∂ kz 2D= = 2Cd cos(k d) - difraction parameter x
dβ2d|φ|
2, where β(ω, ω ) and ω (|φ| ), m m
2ω -(ω +hωm 2
) = -(ωm 2 -2|β|S) e , S - film thickness
γ=
22
π0
137
147
π/2k d┴
-1k , cm||
D>0
D<0
Isofrequency curveMSSW(FEM simulation)
D
γ
BV
MS
WM
SS
W
Bright soliton Dark soliton
γD>0
γD>0
γD<0
γD<0
Bright solitonDark soliton
0
...
f=5.6 GHz
4pM = 1750 G0
H = 1200 Oe0
S = 10 mm
d = 180 mm
Bias magnetic field
Magnetization saturation
YIG thickness
Period (in x-direction)
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
f = 5.4 GHz
z-coordinate (mm)
z-coordinate (mm)
z-coordinate (mm)
z-coordinate (mm)
0
4.4
x-co
ord
inate
(m
m)
1.1
2.2
3.3
4.4
x-co
ord
inate
(m
m)
1.1
2.2
3.3
0
4.4
x-co
ord
ina
te (
mm
)
1.1
2.2
3.3
0
4.4
x-co
ord
ina
te (
mm
)
1.1
2.2
3.3
0
P = -10 dBmin
P = 5dBmin
P = 15 dBmin
P = 30 dBmin
1.01.52.02.53.03.5
00.5
0 0,5 1,0 1,5 2,0 2,5 3,0 3,5Nor
mal
ized
bea
m w
idth
(ar
b. u
n.)
z-coordinate (mm)
Power sweep
-10 dBm
5 dBm
15 dBm
30 dBm
A =0.010
A =0.0250
00 1 2 3 4
5
10
15
20
25
wav
egui
denu
mbe
r
z-coordinate, mm
10
15
20
25
wav
egui
denu
mbe
r
0
5
z-coordinate, mm
Numerical simulation
BLS EXPERIMENTBVMSW
Bright discrete soliton formation
0 1 2 3 4
Transverse position (mm)0 10 20 30 40
BLS
inte
nsity (
arb
.un.)
z-coordinate (mm)
x-co
ord
inate
(m
m)
0
2.25
0 4
z-coordinate (mm)
x-c
oord
inate
(m
m)
0
2.25
0 4
P = 5dBmin
P = 32 dBmin
Transverse position (mm)0 10 20 30 40
BLS
inte
nsity (
arb
.un.)
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
BLS EXPERIMENT
f = 5.5 GHzPower sweep MSSW
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