Significant results of scientific activity in year 2012

One of the most fundamental laws of nature, the so-called no-cloning theorem, states that an unknown quantum state cannot be perfectly copied. This fact has an imminent impact on quantum information processing. For instance, it allows designing inherently secure cryptographic protocols or assures the impossibility of superluminal communication. Although perfect quantum copying is impossible, one can still investigate how well such an operation can be approximated within...