Evidence for Higgs boson production in association with a $t\bar{t}$ pair

The searches for the associated production of a Higgs boson with a ttbar pair ($t\bar{t}H$) with the ATLAS experiment at the LHC are presented. The motivation behind these searches and their importance for finding new physics phenomena is outlined. The searches are split according to the Higgs decay mode, namely into a $b\bar{b}$ pair, multiple charged leptons, a $Z$ boson pair decaying further into four charged leptons, and two photons. For each analysis, the setup, challenges, strategy and results are discussed. The combined result of the four measurements is shown, which provides evidence for the $t\bar{t}H$ production with an observed significance of 4.2 standard deviations compared to an expected significance of 3.8 standard deviations. A short conclusion and outlook is given.