Room-temperature antiferromagnetic memory resistor.
The bistability of ordered spin states in ferromagnets provides the basis for magnetic memory functionality. The latest generation of magnetic random access memories rely on an efficient approach in which magnetic fields are replaced by electrical means for writing and reading the information in ferromagnets. This concept may eventually reduce the sensitivity of ferromagnets to magnetic field perturbations to being a weakness for data retention and the ferromagnetic stray fields to an obstacle for high-density memory integration. Here we report a room-temperature bistable antiferromagnetic (AFM) memory that produces negligible stray fields and is insensitive to strong magnetic fields. We use a resistor made of a FeRh AFM, which orders ferromagnetically roughly 100 K above room temperature, and therefore allows us to set different collective directions for the Fe moments by applied magnetic field. On cooling to room temperature, AFM order sets in with the direction of the AFM moments predetermined by the field and moment direction in the high-temperature ferromagnetic state. For electrical reading, we use an AFM analogue of the anisotropic magnetoresistance. Our microscopic theory modelling confirms that this archetypical spintronic effect, discovered more than 150 years ago in ferromagnets, is also present in AFMs. Our work demonstrates the feasibility of fabricating room-temperature spintronic memories with AFMs, which in turn expands the base of available magnetic materials for devices with properties that cannot be achieved with ferromagnets.
1] Department of Materials Science and Engineering and Department of Physics, University of California, Berkeley, California 94720, USA [2] Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, 12116 Praha 2, Czech Republic [3] Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Praha 6, Czech Republic.
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Marti
1] Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, Bellaterra E-08193, Spain [2] Max Planck Institute of Microstructure Physics, Weinberg 2, Halle D-06120, Germany.
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Fina
Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, Bellaterra E-08193, Spain.
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Frontera
Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
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Liu
1] Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Praha 6, Czech Republic [2] School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
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Wadley
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
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He
Department of Materials Science and Engineering and Department of Physics, University of California, Berkeley, California 94720, USA.
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Paull
Department of Materials Science and Engineering and Department of Physics, University of California, Berkeley, California 94720, USA.
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Clarkson
Institute of Physics ASCR, v.v.i., Na Slovance 2, 182 21 Praha 8, Czech Republic.
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Kudrnovský
1] Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, 12116 Praha 2, Czech Republic [2] Institute of Physics of Materials ASCR, v.v.i., Zizkova 22, Brno 616 62, Czech Republic.
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Turek
Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Praha 6, Czech Republic.
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Kuneš
Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
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Yi
Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
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Chu
National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
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Nelson
Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, California 94720, USA.
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You
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
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Arenholz
Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, California 94720, USA.
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Salahuddin
Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, Bellaterra E-08193, Spain.
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Fontcuberta
1] Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Praha 6, Czech Republic [2] School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
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Jungwirth
1] Department of Materials Science and Engineering and Department of Physics, University of California, Berkeley, California 94720, USA [2] Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
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Ramesh