Dynamically Encircling Exceptional Points: Exact Evolution And Polarization State Conversion
Abstract
We show that a two-level non-Hermitian Hamiltonian with constant off-diagonal exchange elements can be analyzed exactly when the underlying exceptional point is perfectly encircled in the complex plane. The state evolution of this system is explicitly obtained in terms of an ensuing transfer matrix, even for large encirclements, regardless of adiabatic conditions. Our results clearly explain the direction-dependent nature of this process and why in the adiabatic limit its outcome is dominated by a specific eigenstate - irrespective of initial conditions. Moreover, numerical simulations suggest that this mechanism can still persist in the presence of nonlinear effects. We further show that this robust process can be harnessed to realize an optical omnipolarizer: a configuration that generates a desired polarization output regardless of the input polarization state, while from the opposite direction it always produces the counterpart eigenstate.
Publication Date
3-3-2017
Publication Title
Physical Review Letters
Volume
118
Issue
9
Document Type
Article
Personal Identifier
scopus
DOI Link
https://doi.org/10.1103/PhysRevLett.118.093002
Copyright Status
Unknown
Socpus ID
85014643283 (Scopus)
Source API URL
https://api.elsevier.com/content/abstract/scopus_id/85014643283
STARS Citation
Hassan, Absar U.; Zhen, Bo; Soljačić, Marin; Khajavikhan, Mercedeh; and Christodoulides, Demetrios N., "Dynamically Encircling Exceptional Points: Exact Evolution And Polarization State Conversion" (2017). Scopus Export 2015-2019. 4895.
https://stars.library.ucf.edu/scopus2015/4895