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Emergent functions of quantum materials

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Abstract

Materials can harbour quantum many-body systems, most typically in the form of strongly correlated electrons in solids, that lead to novel and remarkable functions thanks to emergence—collective behaviours that arise from strong interactions among the elements. These include the Mott transition, high-temperature superconductivity, topological superconductivity, colossal magnetoresistance, giant magnetoelectric effect, and topological insulators. These phenomena will probably be crucial for developing the next-generation quantum technologies that will meet the urgent technological demands for achieving a sustainable and safe society. Dissipationless electronics using topological currents and quantum spins, energy harvesting such as photovoltaics and thermoelectrics, and secure quantum computing and communication are the three major fields of applications working towards this goal. Here, we review the basic principles and the current status of the emergent phenomena and functions in materials from the viewpoint of strong correlation and topology.

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Figure 1: Concepts in quantum materials.
Figure 2: Electronic phase control of correlated-electron materials.
Figure 3: Multiferroics of spin origin and their magnetoelectric responses.
Figure 4: Emergent magnetic field associated with the non-collinear spin configuration and its consequent physical phenomenon.
Figure 5: Emergent electromagnetic field in momentum space.
Figure 6: Quantum phenomena observed in topological insulator heterostructures.
Figure 7: Emergent electromagnetism in real space.
Figure 8: Majorana fermions in topological superconductors and fractional quantum Hall systems.

Change history

  • 17 October 2017

    In the version of this Review originally published, the notes accompanying refs 4, 6, 7, 10, 15, 39, 53, 57, 59, 64, 65, 67, 73, 93, 105, 112 and 125 were missing. This has now been corrected.

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Acknowledgements

The authors would like to thank M. Uchida, M. Ishida and C. Terakura for their help in preparing the manuscript.

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Correspondence to Yoshinori Tokura.

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Tokura, Y., Kawasaki, M. & Nagaosa, N. Emergent functions of quantum materials. Nature Phys 13, 1056–1068 (2017). https://doi.org/10.1038/nphys4274

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