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Meer, H.*; Schreiber, F.*; Schmitt, C.*; Ramos, R.*; Saito, Eiji; Gomonay, O.*; Sinova, J.*; Baldrati, L.*; Klui, M.*
Nano Letters, 21(1), p.114 - 119, 2021/01
Times Cited Count:51 Percentile:96.99(Chemistry, Multidisciplinary)Baldrati, L.*; Schmitt, C.*; Gomonay, O.*; Lebrun, R.*; Ramos, R.*; Saito, Eiji; Sinova, J.*; Klui, M.*
Physical Review Letters, 125(7), p.077201_1 - 077201_6, 2020/08
Times Cited Count:36 Percentile:91.79(Physics, Multidisciplinary)Baldrati, L.*; Gomonay, O.*; Ross, A.*; Filianina, M.*; Lebrun, R.*; Ramos, R.*; Leveille, C.*; Fuhrmann, F.*; Forrest, T. R.*; Maccherozzi, F.*; et al.
Physical Review Letters, 123(17), p.177201_1 - 177201_6, 2019/10
Times Cited Count:118 Percentile:98.44(Physics, Multidisciplinary)Gomonay, O.*; Yamamoto, Kei; Sinova, J.*
Journal of Physics D; Applied Physics, 51(26), p.264004_1 - 264004_9, 2018/07
Times Cited Count:9 Percentile:42.42(Physics, Applied)Searching for novel spin caloric effects in antiferromagnets we study the properties of thermally activated magnons in the presence of an external spin current and temperature gradient. We predict the spin Peltier effect - generation of a heat flux by spin accumulation - in an antiferromagnetic insulator with cubic or uniaxial magnetic symmetry. This effect is related with spin-current induced splitting of the relaxation times of the magnons with opposite spin direction. We show that the Peltier effect can trigger antiferromagnetic domain wall motion with a force whose value grows with the temperature of a sample. We also demonstrate that the external spin current can induce the magnon spin Seebeck effect.
Yamamoto, Kei; Gomonay, O.*; Sinova, J.*; Schwiete, G.*
Physical Review B, 98(1), p.014406_1 - 014406_24, 2018/07
Times Cited Count:1 Percentile:5.02(Materials Science, Multidisciplinary)Yamane, Yuta*; Ieda, Junichi; Sinova, J.*
Physical Review B, 94(5), p.054409_1 - 054409_8, 2016/08
Times Cited Count:28 Percentile:75.74(Materials Science, Multidisciplinary)We formulate a theory of spin-transfer torques in antiferromagnets, which covers the small to large limits of the exchange coupling energy relative to the kinetic energy of the inter-sublattice electron dynamics. Our theory suggests a natural definition of the efficiency of spin-transfer torques in antiferromagnets in terms of well-defined material parameters, revealing that the charge current couples predominantly to the antiferromagnetic order parameter and the sublattice-canting moment in, respectively, the limits of large and small exchange coupling. The effects can be quantified by analyzing the antiferromagnetic spin-wave dispersions in the presence of charge current: in the limit of large exchange coupling the spin-wave Doppler shift always occurs, whereas, in the opposite limit, the only spin-wave modes to react to the charge current are ones that carry a pronounced sublattice-canting moment. The findings offer a framework for understanding and designing spin-transfer torques in antiferromagnets belonging to different classes of sublattice structures such as, e.g., bipartite and layered antiferromagnets.
Yamane, Yuta*; Ieda, Junichi; Sinova, J.*
Physical Review B, 93(18), p.180408_1 - 180408_5, 2016/05
Times Cited Count:17 Percentile:61.21(Materials Science, Multidisciplinary)Yamane, Yuta*; Hemmatiyan, S.*; Ieda, Junichi; Maekawa, Sadamichi; Sinova, J.*
Scientific Reports (Internet), 4, p.6901_1 - 6901_5, 2014/11
Times Cited Count:14 Percentile:52.23(Multidisciplinary Sciences)Interaction between local magnetization and conduction electrons is responsible for a variety of phenomena in magnetic materials. It has been recently shown that spin current and associated electric voltage can be induced by magnetization that depends on both time and space. This effect, called spinmotive force, provides for a powerful tool for exploring the dynamics and the nature of magnetic textures, as well as a new source for electromotive force. Here we theoretically demonstrate the generation of electric voltages in magnetic bubble array systems subjected to a magnetic field gradient. It is shown by deriving expressions for the electric voltages that the present system offers a direct measure of phenomenological parameter that describes non-adiabaticity in the current induced magnetization dynamics. This spinmotive force opens a door for new types of spintronic devices that exploit the field-gradient.
Okamoto, Naoya*; Kurebayashi, Hidekazu*; Trypiniotis, T.*; Farrer, I.*; Ritchie, D. A.*; Saito, Eiji; Sinova, J.*; Maek, J.*; Jungwirth, T.*; Barnes, C.*
Nature Materials, 13(10), p.932 - 937, 2014/10
Times Cited Count:47 Percentile:85.62(Chemistry, Physical)Ieda, Junichi; Yamane, Yuta*; Hemmatiyan, S.*; Sinova, J.*; Maekawa, Sadamichi
no journal, ,
We show that electric voltage generation (spinmotive force) from magnetic bubble arrays subject to a magnetic field gradient. The formula for the induced voltage is derived and whereby a new method is proposed for determining the magnitude of the phenomenological parameter that measures non-adiabaticity of current-induced magnetization dynamics. This spinmotive force opens up a door for developing a new type of spintronics devices relying on the magnetic field gradient.
Ieda, Junichi; Yamane, Yuta*; Sinova, J.*
no journal, ,
Recently, antiferromagnetic (AFM) materials are generating more attention due to their potential to become a key player in technological applications. To understand spin transport in AFM metals, however, in addition to the s-d exchange interaction that plays a pivotal role in ferromagnetic-based spintronics, the sublattice degree of freedom should be taken into account. In this presentation we theoretically demonstrate electric voltage generation due to spinmotive forces originating from domain wall motion and magnetic resonance in antiferromagnets. This work suggests a new way to observe and explore the dynamics of antiferromagnetic textures by electrical means, an important aspect in the emerging field of antiferromagnetic spintronics. We also formulate spin-transfer torques in antiferromagnetic materials. Taking in the electron-magnetization exchange coupling and the inter-sublattice electron dynamic as model parameters, we examine the two limiting cases where either one of the two is dominant over another. Our work offers a framework for quantitative understanding of spin-transfer torques in different classes of antiferromagnetic materials.
Ieda, Junichi; Yamane, Yuta*; Sinova, J.*
no journal, ,
Recently, spintronics phenomena in antiferromagnets (AFM) attract attention. Especially spin transfer torque (STT) and spinmotive force (SMF) that have been established and play principal roles in ferromagnets become important subjects since they enable us to control and detect AFM dynamics. A few approaches have been theoretically proposed for treating these effects in AFMs but they are still under debate. In this work, we theoretically investigate SMF due to AFM dynamics by incorporating the finite canting between sublattice magnetizations, non-adiabaticity of the electron dynamics, and the Rashba spin-orbit interaction, which were all omitted in previous work. We show that the electric voltages can be generated by field-induced AFM domain wall motion and AFM resonance. This finding is useful as providing an electrical detection method of AFM dynamics and opens up the possibility of materials search for the larger SMF signals.
Yamamoto, Kei; Gomonay, O.*; Sinova, J.*; Schwiete, G.*
no journal, ,
We study a ferromagnetic-antiferromagnetic-normal metal tunneling junction using non-equilibrium Green's function techniques and derive microscopic formulae for various types of spin torque as well as charge and spin conductance. Relative strength of the torques and their dependence on control parameters such as the tunneling probabilities to the two leads are presented. We also discuss dynamical consequences of the different torques. Charge and spin transmission is shown to depend on the angle between the ferromagnetic and antiferromagnetic order parameters. We suggest potential applications of these angular dependences.
Yamamoto, Kei; Smejkal, L.*; Jungwirth, T.*; Sinova, J.*
no journal, ,
Ieda, Junichi; Yamane, Yuta*; Sinova, J.*
no journal, ,