TY - JOUR
T1 - Stable magnetic droplet solitons in spin-transfer nanocontacts
AU - Macià, Ferran
AU - Backes, Dirk
AU - Kent, Andrew D.
N1 - Funding Information:
F.M. acknowledges support from the European Commission (grant no. MC-IOF 253214), from the Catalan Government through the programme COFUND-FP7 and from the Spanish Government (grant no. MAT2011-23698). This research was supported by the National Science Foundation-Division of Materials Research-1309202 and in part by the Army Research Office-Multidisciplinary University Research Initiative (grant no. W911NF-08-1-0317). Research was carried out in part at the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the US Department of Energy, Office of Basic Energy Sciences (contract no. DE-AC02-98CH10886).
Publisher Copyright:
© 2014 Macmillan Publishers Limited. All rights reserved.
PY - 2014/1/1
Y1 - 2014/1/1
N2 - Magnetic thin films with perpendicular magnetic anisotropy have localized excitations that correspond to reversed, dynamically precessing magnetic moments, which are known as magnetic droplet solitons. Fundamentally, these excitations are associated with an attractive interaction between elementary spin-excitations and have been predicted to occur in perpendicularly magnetized materials in the absence of damping1,2. Although damping suppresses these excitations, it can be compensated by spin-transfer torques when an electrical current flows in nanocontacts to ferromagnetic thin films3,4. Theory predicts the appearance of magnetic droplet solitons in nanocontacts at a threshold current5 and, recently, experimental signatures of droplet nucleation have been reported6. However, to date, these solitons have been observed to be nearly reversible excitations, with only partially reversed magnetization. Here, we show that magnetic droplet solitons exhibit a strong hysteretic response in field and current, proving the existence of bistable states: droplet and non-droplet states. In the droplet soliton state we find that the magnetization in the contact is almost fully reversed. These observations, in addition to their fundamental interest, are important to understanding and controlling droplet motion, nucleation and annihilation7-9.
AB - Magnetic thin films with perpendicular magnetic anisotropy have localized excitations that correspond to reversed, dynamically precessing magnetic moments, which are known as magnetic droplet solitons. Fundamentally, these excitations are associated with an attractive interaction between elementary spin-excitations and have been predicted to occur in perpendicularly magnetized materials in the absence of damping1,2. Although damping suppresses these excitations, it can be compensated by spin-transfer torques when an electrical current flows in nanocontacts to ferromagnetic thin films3,4. Theory predicts the appearance of magnetic droplet solitons in nanocontacts at a threshold current5 and, recently, experimental signatures of droplet nucleation have been reported6. However, to date, these solitons have been observed to be nearly reversible excitations, with only partially reversed magnetization. Here, we show that magnetic droplet solitons exhibit a strong hysteretic response in field and current, proving the existence of bistable states: droplet and non-droplet states. In the droplet soliton state we find that the magnetization in the contact is almost fully reversed. These observations, in addition to their fundamental interest, are important to understanding and controlling droplet motion, nucleation and annihilation7-9.
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U2 - 10.1038/nnano.2014.255
DO - 10.1038/nnano.2014.255
M3 - Article
AN - SCOPUS:84926160122
SN - 1748-3387
VL - 9
SP - 992
EP - 996
JO - Nature Nanotechnology
JF - Nature Nanotechnology
IS - 12
ER -