Highlights of Top Quark Measurements with the ATLAS Experiment

Measurements of processes involving single top quarks or top-quark-antiquark pairs are of major importance to check the predictions of the Standard Model or to provide sensitivity to new physics beyond the Standard Model. In the recent years, the ATLAS experiment at the Large Hadron Collider performed precise measurements of top-quark related properties and also measured more complex Standard Model processes associated with top quarks, which have typically very low cross sections compared to the main production modes at the Large Hadron Collider. On this subject, some of the most relevant results released by the ATLAS collaboration in 2021 are presented: the inclusive and differential cross-section measurement of top-quark-antiquark production in association with a $Z$ boson, the cross-section measurement of four top-quark production, the fiducial and differential measurement of the top-quark-antiquark cross section with high transverse momenta of the top quarks, as well as the polarisation measurement of single top quarks (antiquarks) produced in the $t$-channel.