Disappearance of measurement-induced phase transition in a quantum spin system for large sizes
Paranjoy Chaki, Protyush Nandi, Ujjwal Sen, and Subinay Dasgupta
Phys. Rev. A 113, L040201 (2026) - Published 10 April, 2026
Classically, it seems counterintuitive that measurements can drastically alter the overall character of a quantum system, and yet it happens. The authors report that for a quantum spin chain, the measurement-induced entanglement transition is captured in the behavior of the survival probability of the initial state, and moreover, this probability can be calculated analytically for large sizes. The result reveals that as the system size increases, the transition, so prominent at small size, simply disappears, leaving a single (“volume-law”) phase.
























