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Repulsion of Resonance States and Exceptional Points

W. D. Heiss
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Abstract

Level repulsion is associated with exceptional points which are square root singularities of the energies as functions of a (complex) interaction parameter. This is also valid for resonance state energies. Using this concept it is argued that level anti-crossing (crossing) must imply crossing (anti-crossing) of the corresponding widths of the resonance states. Further, itis shown that an encircling of an exceptional point induces a phase change of one wave function but not of the other. An experimental setup is discussed where this phase behaviour which differs from the one encountered at a diabolic point can be observed.

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W. D. Heiss. 1999-09-15. Repulsion of Resonance States and Exceptional Points. https://doi.org/10.1103/physreve.61.929

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