Abstract
The Lindblad equation for a two-level system under an electric field is analyzed by mapping to a linear equation with a non-Hermitian matrix. Exceptional points of the matrix are found to be extensive; the second-order ones are located on lines in a two-dimensional parameter space, while the third-order one is at a point.
GRAPHICAL ABSTRACT
![](/cms/asset/a20937f3-ce59-4d2e-bc94-fad641396711/tmph_a_1593535_uf0001_oc.jpg)
Acknowledgments
The present study was carried out in an exceptionally pleasant collaboration with Prof. Nimrod Moiseyev when he invited the present author for a splendid stay at his group in Technion. In the normal situation, he would be on the list of the authors, but it is obviously awkward to have him as a co-author of the paper that the present author dedicates to him.
Disclosure statement
No potential conflict of interest was reported by the author.
ORCID
Naomichi Hatano http://orcid.org/0000-0003-0277-1856