  A search is presented for the pair production of light scalar top quarks in
sqrt(s) = 7 TeV proton-proton collisions recorded with the ATLAS detector at
the Large Hadron Collider. This analysis uses the full data sample collected
during 2011 that corresponds to a total integrated luminosity of 4.7 fb-1.
Light scalar top quarks are searched for in events with two opposite-sign
leptons (e, mu), large missing transverse momentum and at least one jet in the
final state. No excess over Standard Model expectations is found, and the
results are interpreted under the assumption that the light scalar top decays
to a b-quark in addition to an on-shell chargino whose decay occurs through a
virtual W boson. If the chargino mass is 106 GeV, light scalar top quark masses
up to 130 GeV are excluded for neutralino masses below 70 GeV.
