We report on two measurements done by ATLAS in a context of exploring the jet quenching physics at LHC: the jet fragmentation measurement and the measurement of neighbouring jet production. Both of these measurements were done using the data collected in 2011 Pb+Pb run providing Pb+Pb collisions at root s(NN) = 2.76 TeV.
These measurements are expected to provide an insight into the modifications of jets initiated by partons passing through hot and dense QCD matter created in heavy ion collisions.