[BM25] Superposition Detection and QMA with Non-Collapsing Measurements

Authors: Roozbeh Bassirian, Kunal Marwaha | Venue: Quantum 2025 | Source

Abstract

We prove that QMA equipped with a single non-collapsing measurement equals NEXP, resolving an open question of Aaronson. A non-collapsing measurement allows the verifier to measure a quantum state without disturbing it — a superpower unavailable in standard quantum mechanics. The result follows as a corollary of the QMA+ = NEXP theorem from [BFM24]: given a non-collapsing measurement, the verifier can check that a proof has non-negative amplitudes in any desired basis, effectively simulating a QMA+ verifier.