'Quantum proofs' really were more powerful than classical proofs: a 20-year-old mystery resolved

Explanation

In June 2026, at an international conference on quantum computing theory, a team of four researchers won the best paper award. They resolved the question of whether quantum proofs can be replaced by classical proofs, a problem that had remained unsolved for more than 20 years. A mathematical proof is normally a document that can be read over and over, but a "proof" in the quantum world is a quantum state itself, which is destroyed once it is measured. Turning this fragile property to their advantage, the researchers showed that there exist problems that only quantum proofs can solve. This achievement was featured by Quanta Magazine on July 6, 2026.