Heavy Ion Physics with the ATLAS Detector

The heavy-ion program at the Large Hadron Collider has started up in November 2010 by three experiments including ATLAS, a multipurpose detector originally constructed to study high-energy proton-proton collisions, which now turns out to be an excellent tool for studying nuclear interactions. In this talk first results from the lead-lead run at sqrt{s_{NN}}=2.76 TeV based on minimum bias data sample are reviewed. In particular an observation of the centrality-dependent di-jet asymmetry is reported. Also a centrality-dependent suppression in the yield of $J/Psi$ mesons decaying to $mu^+mu^-$ pairs is discussed along with an observation of the $Z$ boson production. These evidences may bring new insight to the primordial universe where a hot, dense medium of quarks and gluons may have prevailed.