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Non-Hermitian physics and PT symmetry

Nature Physics volume 14, pages 11–19 (2018)Cite this article

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Abstract

In recent years, notions drawn from non-Hermitian physics and parity–time (PT) symmetry have attracted considerable attention. In particular, the realization that the interplay between gain and loss can lead to entirely new and unexpected features has initiated an intense research effort to explore non-Hermitian systems both theoretically and experimentally. Here we review recent progress in this emerging field, and provide an outlook to future directions and developments.

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Figure 1: Schematic presentation of a PT-coupled system and first experimental observations of spontaneous PT symmetry breaking.
Figure 2: Unidirectional invisibility and PT-symmetric arrays.
Figure 3: PT-symmetric lasing systems and exceptional point encirclement.
Figure 4: Future directions in PT-symmetric optics.

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Acknowledgements

The authors gratefully acknowledge the financial support from NSF CAREER Award (ECCS-1454531), NSF (ECCS-1545804, DMR-1420620, EECS-1757025), AFOSR (FA9550-14-1-0037), ARO (W911NF-16-1-0013, W911NF-17-1-0481), and ONR (N00014-16-1-2640). K.G.M. and S.R. were funded by the European Commission under projects NOLACOME (PIOF 303228), NHQWAVE (MSCA-RISE 691209), and by the Austrian Science Fund (FWF) through Projects No. F25 (SFB IR-ON), No. F49 (SFB NextLite), No. I1142-N27 (GePartWave). K.G.M. was also supported by the European Union Seventh Framework Program (FP7-REGPOT-2012-2013-1) under grant agreement 316165.

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Authors and Affiliations

  1. Department of Physics and Henes Center for Quantum Phenomena Michigan Technological University, Michigan Technological University, Houghton, 49931, Michigan, USA

    Ramy El-Ganainy

  2. Physics Department, Crete Center for Quantum Complexity and Nanotechnology, University of Crete, PO Box 2208, Heraklion, 71003, Greece

    Konstantinos G. Makris

  3. College of Optics & Photonics-CREOL, University of Central Florida, Orlando, 32816, Florida, USA

    Mercedeh Khajavikhan & Demetrios N. Christodoulides

  4. Mathematics Department, Florida State University, Tallahassee, 32306, Florida, USA

    Ziad H. Musslimani

  5. Institute for Theoretical Physics, Vienna University of Technology (TU-Wien), Vienna, A-1040, Austria

    Stefan Rotter

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El-Ganainy, R., Makris, K., Khajavikhan, M. et al. Non-Hermitian physics and PT symmetry. Nature Phys 14, 11–19 (2018). https://doi.org/10.1038/nphys4323

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