Thermal effects on quantum cloning and entanglement broadcasting

Quantum cloning in the vicinity of a thermal environment is analyzed. First of all, we consider the situation in which only the initial state of our machinery, because of weak coupling to its surroundings, deviates from its purity. Later on, we inspect how the fidelities of symmetric universal and phase covariant cloning are modified when a simple dissipating spin one-half particle is duplicated. Finally, cloning of the entanglement associated with thermally diluted qubit pairs, via three (one local and two nonlocal) scenarios, is studied. Depending on which scenario is being used, we get some temperature and state dependent inequalities over which our clones are inseparable. “Joint work with A. T. Rezakhani”