Giulio Chiribella: Quantum replication at the Heisenberg limit

Giulio Chiribella, Tsinghua University

Abstract

No process in nature can perfectly clone an arbitrary quantum state. But is it possible to engineer processes that replicate quantum information with vanishingly small error? Here we demonstrate the possibility of probabilistic super-replication phenomena where N equally prepared quantum systems are transformed into a much larger number M nearly perfect replicas, with an error that rapidly vanishes whenever M is small compared to the square of N. The quadratic replication rate is the ultimate limit imposed by quantum mechanics and is fundamentally linked with the Heisenberg limit of quantum metrology.