Quantum uniqueness

TL;DR

Quantum uniqueness is a fundamental property showing that two different quantum systems cannot always produce identical measurement results, highlighting a key difference from classical systems and relating to the inherent randomness of quantum measurements.

Contribution

The paper proves that quantum systems cannot always produce identical results after the same measurement, establishing a new fundamental aspect called quantum uniqueness.

Findings

Quantum systems cannot always yield identical results after the same measurement.

Quantum uniqueness has no classical analog.

It is closely related to the objective randomness of quantum measurements.

Abstract

In the classical world one can construct two identical systems which have identical behavior and give identical measurement results. We show this to be impossible in the quantum domain. We prove that after the same quantum measurement two different quantum systems cannot yield always identical results, provided the possible measurement results belong to a non orthogonal set. This is interpreted as quantum uniqueness - a quantum feature which has no classical analog. Its tight relation with objective randomness of quantum measurements is discussed.