Quasi-particles in weak perturbations of non-interacting quantum lattice systems

We consider a general weak perturbation of a non-interacting quantum lattice system with a non-degenerate gapped ground state. We prove that the presence of isolated eigenvalues in the spectrum of the decoupled model leads to the existence of quasi-particles in the perturbed model. Also, a scatterin...

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Bibliographic Details
Published in:arXiv.org 2004-11
Main Author: Yarotsky, D A
Format: Article
Language:English
Subjects:
Eigenvalues
Online Access:Get full text
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Summary:We consider a general weak perturbation of a non-interacting quantum lattice system with a non-degenerate gapped ground state. We prove that the presence of isolated eigenvalues in the spectrum of the decoupled model leads to the existence of quasi-particles in the perturbed model. Also, a scattering theory for asymptotically free many-particle states is developed.
ISSN:2331-8422