Condensed matter models as a test bed for quantum information concepts

- Condensed matter systems are considered good candidates for quantum technology devices due to their natural quantum fluctuations
- the von Neumann entropy and the linear entropy are considered qualitatively equivalent
- we investigate both linear and von Neumann entropies in homogeneous, superlattice and disordered Hubbard chains.
- we find regimes of parameters for which the linear entropy fails in reproducing the qualitative behavior of the von Neumann entropy.
-This then may lead to incorrect predictions i) of maximum and minimum entanglement states and ii) of quantum phase transition