The magnetization dynamics of a multilayer rhomboid shaped nanomagnet pair is investigated using micro-focused Brillouin light scattering spectroscopy. The multilayer structure consists of two permalloy layers separated by a nonmagnetic Cr spacer layer. As compared with a single-layer rhomboid shaped nanomagnet pair with two distinct magnetic ground states (ferromagnetic and antiferromagnetic), the multilayer nanomagnetic pair displays multiple magnetic ground states upon different initialization fields due to the presence of both in-plane and out-of-plane dipolar coupling. The dynamic response as a function of initialization field has been systematically investigated. Distinct microwave absorption behavior and resonance frequency shift are observed when the nanomagnet pair is switched into different magnetic ground states. Micromagnetic simulations validate our experimental observations.

Topics
Nanomagnets, Ferromagnetic materials, Magnetic ordering, Magnetization dynamics, Digital circuits, Microwave absorptions, Brillouin spectroscopy, Spectroscopy, Alloys, Chemical compounds
1.
R. L.
 
Stamps
,
S.
 
Breitkreutz
,
J.
 
Åkerman
,
A. V.
 
Chumak
,
Y.
 
Otani
,
G. E. W.
 
Bauer
,
J.-U.
 
Thiele
,
M.
 
Bowen
,
S. A.
 
Majetich
,
M.
 
Kläui
,
I. L.
 
Prejbeanu
,
B.
 
Dieny
,
N. M.
 
Dempsey
, and
B.
 
Hillebrands
,
J. Phys. D: Appl. Phys.
 
47
,
333001
(
2014
).
https://doi.org/10.1088/0022-3727/47/33/333001
Google Scholar
Crossref
Search ADS
 
2.
M.
 
Krawczyk
 and
D.
 
Grundler
,
J. Phys.: Condens. Matter
 
26
,
123202
(
2014
).
https://doi.org/10.1088/0953-8984/26/12/123202
Google Scholar
Crossref
Search ADS
PubMed
 
3.
M. T.
 
Niemier
,
G. H.
 
Bernstein
,
G.
 
Csaba
,
A.
 
Dingler
,
X. S.
 
Hu
,
S.
 
Kurtz
,
S.
 
Liu
,
J.
 
Nahas
,
W.
 
Porod
,
M.
 
Siddiq
, and
E.
 
Varga
,
J. Phys.: Condens. Matter
 
23
,
493202
(
2011
).
https://doi.org/10.1088/0953-8984/23/49/493202
Google Scholar
Crossref
Search ADS
PubMed
 
4.
A.
 
Haldar
,
D.
 
Kumar
, and
A. O.
 
Adeyeye
,
Nat. Nanotechnol.
 
11
,
437
(
2016
).
https://doi.org/10.1038/nnano.2015.332
Google Scholar
Crossref
Search ADS
PubMed
 
5.
M. P.
 
Kostylev
,
A. A.
 
Serga
,
T.
 
Schneider
,
B.
 
Leven
, and
B.
 
Hillebrands
,
Appl. Phys. Lett.
 
87
,
153501
(
2005
).
https://doi.org/10.1063/1.2089147
Google Scholar
Crossref
Search ADS
 
6.
T.
 
Schneider
,
A. A.
 
Serga
,
B.
 
Leven
,
B.
 
Hillebrands
,
R. L.
 
Stamps
, and
M. P.
 
Kostylev
,
Appl. Phys. Lett.
 
92
,
022505
(
2008
).
https://doi.org/10.1063/1.2834714
Google Scholar
Crossref
Search ADS
 
7.
S.
 
Wintz
,
V.
 
Tiberkevich
,
M.
 
Weigand
,
J.
 
Raabe
,
J.
 
Lindner
,
A.
 
Erbe
,
A.
 
Slavin
, and
J.
 
Fassbender
,
Nat. Nanotechnol.
 
11
,
948
(
2016
).
https://doi.org/10.1038/nnano.2016.117
Google Scholar
Crossref
Search ADS
PubMed
 
8.
A. V.
 
Chumak
,
A. A.
 
Serga
, and
B.
 
Hillebrands
,
Nat. Commun.
 
5
,
4700
(
2014
).
https://doi.org/10.1038/ncomms5700
Google Scholar
Crossref
Search ADS
PubMed
 
9.
K.
 
Wagner
,
A.
 
Kakay
,
K.
 
Schultheiss
,
A.
 
Henschke
,
T.
 
Sebastian
, and
H.
 
Schultheiss
,
Nat. Nanotechnol.
 
11
,
432
(
2016
).
https://doi.org/10.1038/nnano.2015.339
Google Scholar
Crossref
Search ADS
PubMed
 
10.
D. A.
 
Allwood
,
G.
 
Xiong
,
C. C.
 
Faulkner
,
D.
 
Atkinson
,
D.
 
Petit
, and
R. P.
 
Cowburn
,
Science
 
309
,
1688
(
2005
).
https://doi.org/10.1126/science.1108813
Google Scholar
Crossref
Search ADS
PubMed
 
11.
D.
 
Kumar
,
S.
 
Barman
, and
A.
 
Barman
,
Sci. Rep.
 
4
,
4108
(
2014
).
https://doi.org/10.1038/srep04108
Google Scholar
Crossref
Search ADS
PubMed
 
12.
J.
 
Ding
 and
A. O.
 
Adeyeye
,
Appl. Phys. Lett.
 
101
,
103117
(
2012
).
https://doi.org/10.1063/1.4751259
Google Scholar
Crossref
Search ADS
 
13.
J.
 
Ding
,
M.
 
Kostylev
, and
A. O.
 
Adeyeye
,
Appl. Phys. Lett.
 
100
,
073114
(
2012
).
https://doi.org/10.1063/1.3687177
Google Scholar
Crossref
Search ADS
 
14.
N.
 
D'Souza
,
J.
 
Atulasimha
, and
S.
 
Bandyopadhyay
,
J. Phys. D: Appl. Phys.
 
44
,
265001
(
2011
).
https://doi.org/10.1088/0022-3727/44/26/265001
Google Scholar
Crossref
Search ADS
 
15.
Y.
 
Kobljanskyj
,
G.
 
Melkov
,
K.
 
Guslienko
,
V.
 
Novosad
,
S. D.
 
Bader
,
M.
 
Kostylev
, and
A.
 
Slavin
,
Sci. Rep.
 
2
,
478
(
2012
).
https://doi.org/10.1038/srep00478
Google Scholar
Crossref
Search ADS
PubMed
 
16.
M.
 
Vogel
,
A. V.
 
Chumak
,
E. H.
 
Waller
,
T.
 
Langner
,
V. I.
 
Vasyuchka
,
B.
 
Hillebrands
, and
G.
 
von Freymann
,
Nat. Phys.
 
11
,
487
(
2015
).
https://doi.org/10.1038/nphys3325
Google Scholar
Crossref
Search ADS
 
17.
A.
 
Haldar
 and
A. O.
 
Adeyeye
,
ACS Nano
 
10
,
1690
(
2016
).
https://doi.org/10.1021/acsnano.5b07849
Google Scholar
Crossref
Search ADS
PubMed
 
18.
A.
 
Haldar
 and
A. O.
 
Adeyeye
,
Appl. Phys. Lett.
 
108
,
022405
(
2016
).
https://doi.org/10.1063/1.4939852
Google Scholar
Crossref
Search ADS
 
19.
C.
 
Tian
 and
A. O.
 
Adeyeye
,
Appl. Phys. Lett.
 
111
,
152404
(
2017
).
https://doi.org/10.1063/1.4995317
Google Scholar
Crossref
Search ADS
 
20.
M. J.
 
Donahue
 and
D. G.
 
Porter
,
Interagency Report No. NISTIR 6376
, National Institute of Standards and Technology, Gaithersburg, MD,
1999
.
21.
S. O.
 
Demokritov
 and
V. E.
 
Demidov
,
IEEE Trans. Magn.
 
44
,
6
(
2008
).
https://doi.org/10.1109/TMAG.2007.910227
Google Scholar
Crossref
Search ADS
 
22.
T.
 
Sebastian
,
K.
 
Schultheiss
,
B.
 
Obry
,
B.
 
Hillebrands
, and
H.
 
Schultheiss
,
Front. Phys.
 
3
,
35
(
2015
).
https://doi.org/10.3389/fphy.2015.00035
Google Scholar
Crossref
Search ADS
 
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