Julia set in quantum evolution: The case of dynamical quantum phase transitions
Phys. Rev. B 113, 024115 – Published 26 January, 2026
DOI: https://doi.org/10.1103/sbdw-2ly3
Abstract
Dynamical quantum phase transitions (DQPTs) are a class of nonequilibrium phase transitions that occur in many-body quantum systems during real-time evolution, rather than through parameter tuning as in conventional phase transitions. This paper presents an exact analytical approach to studying DQPTs by combining complex dynamics with the real-space renormalization group. Renormaliztion group transformations are interpreted as iterated maps on the complex plane, establishing a connection between DQPTs and the Julia set, the boundary separating the basins of attraction of the stable fixed points. This framework is applied to a quantum quench in the one-dimensional transverse-field Ising model, where we examine the sensitivity of DQPTs to variations in boundary conditions. We show that altering the topology of the spin chain can suppress DQPTs and provide a qualitative explanation based on quantum speed limits.