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Phases of Wave Functions and Level Repulsion

W. D. Heiss
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Abstract

Avoided level crossings are associated with exceptional points which are the singularities of the spectrum and eigenfunctions, when they are considered as functions of a coupling parameter. It is shown that the wave function of {\it one} state changes sign but not the other, if the exceptional point is encircled in the complex plane. An experimental setup is suggested where this peculiar phase change could be observed.

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W. D. Heiss. 1999-01-11. Phases of Wave Functions and Level Repulsion. https://doi.org/10.1007/s100530050339

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