English

PT-symmetric lattices with spatially extended gain/loss are generically unstable

Exactly Solvable and Integrable Systems 2015-06-12 v1 Mathematical Physics math.MP Quantum Physics

Abstract

We illustrate, through a series of prototypical examples, that linear parity-time (PT) symmetric lattices with extended gain/loss profiles are generically unstable, for any non-zero value of the gain/loss coefficient. Our examples include a parabolic real potential with a linear imaginary part and the cases of no real and constant or linear imaginary potentials. On the other hand, this instability can be avoided and the spectrum can be real for localized or compact PT-symmetric potentials. The linear lattices are analyzed through discrete Fourier transform techniques complemented by numerical computations.

Keywords

Cite

@article{arxiv.1211.5815,
  title  = {PT-symmetric lattices with spatially extended gain/loss are generically unstable},
  author = {D. E. Pelinovsky and P. G. Kevrekidis and D. J. Frantzeskakis},
  journal= {arXiv preprint arXiv:1211.5815},
  year   = {2015}
}

Comments

6 pages, 4 figures