%0 Journal Article
%T A pedagogical approach to the Magnus expansion
%A Blanes, S.
%A Casas, F.
%A Oteo, J. A.
%A Ros, J.
%J European Journal of Physics
%D 2010
%V 31
%N 4
%I Iop Publishing Ltd
%@ 0143-0807
%G English
%F Blanes_etal2010
%O ISI:000279393800024
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=259), last updated on Thu, 17 Feb 2011 12:19:38 +0000
%X Time-dependent perturbation theory as a tool to compute approximate solutions of the Schrodinger equation does not preserve unitarity. Here we present, in a simple way, how the Magnus expansion (also known as exponential perturbation theory) provides such unitary approximate solutions. The purpose is to illustrate the importance and consequences of such a property. We suggest that the Magnus expansion may be introduced to students in advanced courses of quantum mechanics.
%R 10.1088/0143-0807/31/4/020
%U https://doi.org/10.1088/0143-0807/31/4/020
%P 907-918