Measurements of ttbar and single top quark production at ATLAS

This article summarises on ttbar and single top-quark production cross-sections obtained with the ATLAS detector using pp collisions data at a centre-of-mass energy of 7 TeV collected in 2011. In particular, for the single top-quark production the results are interpreted in terms of the CKM matrix element |Vtb|. Any observed deviation from the SM predictions would give hints to different models of new physics. Searches for flavour changing neutral currents (FCNC) in single top-quark events are also presented.