Annihilation of exceptional points from different Dirac valleys in a 2D photonic system

M. Król, I. Septembre, P. Oliwa, M. Kędziora, K. Łempicka-Mirek, M. Muszyński, R. Mazur, P. Morawiak, W. Piecek, P. Kula, W. Bardyszewski, P. G. Lagoudakis, D. D. Solnyshkov (), G. Malpuech (), B. Piętka () and J. Szczytko ()
Additional contact information
M. Król: Institute of Experimental Physics, Faculty of Physics, University of Warsaw
I. Septembre: Institut Pascal, PHOTON-N2, Université Clermont Auvergne, CNRS, Clermont INP
P. Oliwa: Institute of Experimental Physics, Faculty of Physics, University of Warsaw
M. Kędziora: Institute of Experimental Physics, Faculty of Physics, University of Warsaw
K. Łempicka-Mirek: Institute of Experimental Physics, Faculty of Physics, University of Warsaw
M. Muszyński: Institute of Experimental Physics, Faculty of Physics, University of Warsaw
R. Mazur: Institute of Applied Physics, Military University of Technology
P. Morawiak: Institute of Applied Physics, Military University of Technology
W. Piecek: Institute of Applied Physics, Military University of Technology
P. Kula: Institute of Chemistry, Military University of Technology
W. Bardyszewski: Institute of Theoretical Physics, Faculty of Physics, University of Warsaw
P. G. Lagoudakis: Skolkovo Institute of Science and Technology
D. D. Solnyshkov: Institut Pascal, PHOTON-N2, Université Clermont Auvergne, CNRS, Clermont INP
G. Malpuech: Institut Pascal, PHOTON-N2, Université Clermont Auvergne, CNRS, Clermont INP
B. Piętka: Institute of Experimental Physics, Faculty of Physics, University of Warsaw
J. Szczytko: Institute of Experimental Physics, Faculty of Physics, University of Warsaw

Nature Communications, 2022, vol. 13, issue 1, 1-6

Abstract: Abstract Topological physics relies on Hamiltonian’s eigenstate singularities carrying topological charges, such as Dirac points, and – in non-Hermitian systems – exceptional points (EPs), lines or surfaces. So far, the reported non-Hermitian topological transitions were related to the creation of a pair of EPs connected by a Fermi arc out of a single Dirac point by increasing non-Hermiticity. Such EPs can annihilate by reducing non-Hermiticity. Here, we demonstrate experimentally that an increase of non-Hermiticity can lead to the annihilation of EPs issued from different Dirac points (valleys). The studied platform is a liquid crystal microcavity with voltage-controlled birefringence and TE-TM photonic spin-orbit-coupling. Non-Hermiticity is provided by polarization-dependent losses. By increasing the non-Hermiticity degree, we control the position of the EPs. After the intervalley annihilation, the system becomes free of any band singularity. Our results open the field of non-Hermitian valley-physics and illustrate connections between Hermitian topology and non-Hermitian phase transitions.

Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/s41467-022-33001-9 Abstract (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:natcom:v:13:y:2022:i:1:d:10.1038_s41467-022-33001-9

Ordering information: This journal article can be ordered from
https://www.nature.com/ncomms/

DOI: 10.1038/s41467-022-33001-9

Access Statistics for this article

Nature Communications is currently edited by Nathalie Le Bot, Enda Bergin and Fiona Gillespie

More articles in Nature Communications from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().