Quantum Statistical Complexity Measure as a Signaling of Correlation Transitions

We introduce a quantum version for the statistical complexity measure, in the context of quantum information theory, and use it as a signaling function of quantum order–disorder transitions. We discuss the possibility for such transitions to characterize interesting physical phenomena, as quantum phase transitions, or abrupt variations in correlation distributions. We apply our measure on two exactly solvable Hamiltonian models: the [Formula: see text]-Quantum Ising Model (in the single-particle reduced state), and on Heisenberg XXZ spin- [Formula: see text] chain (in the two-particle reduced state). We analyze its behavior across quantum phase transitions for finite system sizes, as well as in the thermodynamic limit by using Bethe Ansatz technique.