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Nan T, Quintela CX, Irwin J, Gurung G, Shao DF, Gibbons J, Campbell N, Song K, Choi SY, Guo L, Johnson RD, Manuel P, Chopdekar RV, Hallsteinsen I, Tybell T, Ryan PJ, Kim JW, Choi Y, Radaelli PG, Ralph DC, Tsymbal EY, Rzchowski MS, Eom CB. Controlling spin current polarization through non-collinear antiferromagnetism. Nat Commun 2020; 11:4671. [PMID: 32938910 PMCID: PMC7494910 DOI: 10.1038/s41467-020-17999-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 07/22/2020] [Indexed: 11/09/2022] Open
Abstract
The interconversion of charge and spin currents via spin-Hall effect is essential for spintronics. Energy-efficient and deterministic switching of magnetization can be achieved when spin polarizations of these spin currents are collinear with the magnetization. However, symmetry conditions generally restrict spin polarizations to be orthogonal to both the charge and spin flows. Spin polarizations can deviate from such direction in nonmagnetic materials only when the crystalline symmetry is reduced. Here, we show control of the spin polarization direction by using a non-collinear antiferromagnet Mn3GaN, in which the triangular spin structure creates a low magnetic symmetry while maintaining a high crystalline symmetry. We demonstrate that epitaxial Mn3GaN/permalloy heterostructures can generate unconventional spin-orbit torques at room temperature corresponding to out-of-plane and Dresselhaus-like spin polarizations which are forbidden in any sample with two-fold rotational symmetry. Our results demonstrate an approach based on spin-structure design for controlling spin-orbit torque, enabling high-efficient antiferromagnetic spintronics. In the typical spin-hall effect, spin-current, charge current, and spin polarisation are all mutually perpendicular, a feature enforced by symmetry. Here, using an anti-ferromagnet with a triangular spin structure, the authors demonstrate a spin-hall effect without a perpendicular spin alignment.
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Affiliation(s)
- T Nan
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - C X Quintela
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - J Irwin
- Department of Physics, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - G Gurung
- Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588, USA
| | - D F Shao
- Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588, USA
| | - J Gibbons
- Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, 14853, USA
| | - N Campbell
- Department of Physics, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - K Song
- Department of Materials Modeling and Characterization, KIMS, Changwon, 51508, South Korea
| | - S -Y Choi
- Department of Materials Science and Engineering, POSTECH, Pohang, 37673, South Korea
| | - L Guo
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - R D Johnson
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK.,ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK.,Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK
| | - P Manuel
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK
| | - R V Chopdekar
- Advanced Light Source, Lawrence Berkeley National Laboratory (LBNL), 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - I Hallsteinsen
- Advanced Light Source, Lawrence Berkeley National Laboratory (LBNL), 1 Cyclotron Road, Berkeley, CA, 94720, USA.,Department of Electronic Systems, Norwegian University of Science and Technology, Trondheim, 7491, Norway
| | - T Tybell
- Department of Electronic Systems, Norwegian University of Science and Technology, Trondheim, 7491, Norway
| | - P J Ryan
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA.,School of Physical Sciences, Dublin City University, Dublin, 11, Ireland
| | - J -W Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Y Choi
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - P G Radaelli
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK
| | - D C Ralph
- Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, 14853, USA.,Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, 14853, USA
| | - E Y Tsymbal
- Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588, USA
| | - M S Rzchowski
- Department of Physics, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - C B Eom
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA.
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Bolstad T, Lysne E, Hallsteinsen I, Arenholz E, Österberg UL, Tybell T. Effect of (1 1 1)-oriented strain on the structure and magnetic properties of La 0.7Sr 0.3MnO 3 thin films. J Phys Condens Matter 2018; 30:255702. [PMID: 29757162 DOI: 10.1088/1361-648x/aac468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Using strain, i.e. subtle changes in lattice constant in a thin film induced by the underlying substrate, opens up intriguing new ways to control material properties. We present a study of the effects of strain on structural and ferromagnetic properties of (1 1 1)pc-oriented La0.7Sr0.3MnO3 epitaxial thin films grown on NdGaO3, SrTiO3, and DyScO3 substrates. (The subscript pc denotes the pseudo-cubic symmetry.) The results show that La0.7Sr0.3MnO3 assumes a monoclinic unit cell on NdGaO3 and DyScO3 and a rhombohedral unit cell on SrTiO3. For La0.7Sr0.3MnO3 on NdGaO3 and DyScO3 a uniaxial magnetic anisotropy is found, while La0.7Sr0.3MnO3 on SrTiO3 is magnetically isotropic. The Néel model is used to explain the anisotropy of the thin films on NdGaO3 and SrTiO3, however, for La0.7Sr0.3MnO3 on DyScO3 the effect of octahedral rotations needs to be included through the single ion model. Through examination of the Curie temperature of the strained films we suggest that (1 1 1)-strain has a different effect on the Jahn-Teller splitting of e g and t 2g electron levels than what is seen in (0 0 1)pc-oriented La0.7Sr0.3MnO3 thin films.
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Affiliation(s)
- T Bolstad
- Department of Electronic Systems, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway
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