Eigenstates and instabilities of chains with embedded defects.
Chaos
; 23(2): 023109, 2013 Jun.
Article
en En
| MEDLINE
| ID: mdl-23822474
ABSTRACT
We consider the eigenvalue problem for one-dimensional linear Schrödinger lattices (tight-binding) with an embedded few-sites linear or nonlinear, Hamiltonian or non-conservative defect (an oligomer). Such a problem arises when considering scattering states in the presence of (generally complex) impurities as well as in the stability analysis of nonlinear waves. We describe a general approach based on a matching of solutions of the linear portions of the lattice at the location of the oligomer defect. As specific examples, we discuss both linear and nonlinear, Hamiltonian and PT-symmetric dimers and trimers. In the linear case, this approach provides us a handle for semi-analytically computing the spectrum [this amounts to the solution of a polynomial equation]. In the nonlinear case, it enables the computation of the linearization spectrum around the stationary solutions. The calculations showcase the oscillatory instabilities that strongly nonlinear states typically manifest.
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Base de datos:
MEDLINE
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En
Revista:
Chaos
Asunto de la revista:
CIENCIA
Año:
2013
Tipo del documento:
Article
País de afiliación:
Estados Unidos