This paper addresses the problem of computing the eigenvalues lying in the gaps of the essential spectrum of a periodic Schrödinger operator perturbed by a fast decreasing potential. We use a recently developed technique, the so-called quadratic projection method, in order to achieve convergence free from spectral pollution. We describe the theoretical foundations of the method in detail and illustrate its effectiveness by several examples. © 2007 IOP Publishing Ltd.
|Number of pages||11|
|Journal||Journal of Physics A: Mathematical and Theoretical|
|Publication status||Published - 27 Jul 2007|