W. D. Heiss
Published 1999-01-11Version 1
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.
Comments: 4 pages Latex, 2 figures encapsulated postscripts (*.epsi) submitted to The European Physical Journal D
The Chirality of Exceptional Points
Dynamically encircling an exceptional point in a real quantum system
Optical lattices with exceptional points in the continuum
