Top quark pair properties in the production and decays of ttbar events at ATLAS

In proton-proton collisions at the LHC, pairs of top and anti-top quarks are expected to be mostly produced through gluon fusion. Making use of the large number of top quark pairs collected, we present measurements of the spin correlation between top and anti-top quarks using several variables and discuss their sensitivity to new physics. In addition, we present measurements of the top quark polarisation predicted in models with CP-conserving and CP-violating processes.