Optimal compression for identically prepared qubit states
  We establish the ultimate limits to the compression of sequences of identically prepared qubits. The limits are determined by Holevo's information quantity and are attained through use of the optimal universal cloning machine, which finds here a novel application to quantum Shannon theory. 
Yuxiang Yang, Giulio Chiribella, and Masahito Hayashi
quant-ph cs.IT math-ph math.IT math.MP