Abstract

arXiv:2312.00132 joint work with Campbell McLauchlan and Benjamin Béri

Recently discovered measurement-induced transitions (MIPTs) in entanglement are phase transitions in classical simulability. However, some highly-entangling dynamics (e.g., integrable systems or Clifford circuits) are easy to classically simulate. Here, we study simulability transitions beyond entanglement by asking how the dynamics of magic competes with measurements. We find distinct MIP Ts in magic, simulability, and entanglement. We identify dynamical “stabilizer-purification” as the mechanism driving the magic transition. En route, we use Pauli-based computation to distill the quantum essence of the dynamics to a set of measurements. We link stabilizer-purification to “magic fragmentation” wherein these measurements separate into disjoint, O(1)-weight blocks, and relate this to the spread of magic in the original circuit becoming arrested.