No-cloning with unitary scaling

TL;DR

This paper proves that it is impossible to create a U-copy of an unknown quantum pure state using any unitary operator, extending the quantum no-cloning principle.

Contribution

It introduces the concept of U-copy and demonstrates the impossibility of creating such copies for arbitrary unknown states with unitary evolution.

Findings

U-copy of an arbitrary unknown quantum state cannot be produced by unitary evolution.

The paper generalizes the no-cloning principle to include unitary scaling operations.

Confirms the fundamental limits of quantum state replication using unitary transformations.

Abstract

It is known that the classical information like strings of bits can be copied. In 1982, Wootters and Zurek proposed the quantum no-cloning principle. No-cloning principle says that it is impossible to make an identical copy of an arbitrary unknown quantum pure state by using unitary evolution. In this paper, we call U $|\psi>$, where U is any unitary operator, a U-copy of the state $|{\psi}>$ and show it is impossible to make a U-copy of an arbitrary unknown quantum pure state by using unitary evolution.