Quantum information in many-body physics (Dr. U. Marzolino)

The first is quantum information with identical particles. I will start with a careful definition which takes into account the impossibility to distinguish particles, and which reduces to the usual definition for distinguishable particles. I will then show that entanglement of identical particles is easily quantified or witnessed when the total particle number is conserved, and show the effects of noise. These features are manifestations of a geometry of entangled states very different from that of distinguishable particles.

The second topic that I will discuss is the characterization of steady states of quantum spin chains using the quantum Fisher information. This approach enables to identify both regimes of quantum enhanced metrology and quantum non-equilibrium phase transition. In particular, I will show the XXZ model with boundary Markovian noise, which exhibits a critical phase with infinitely many critical points and without local order parameters at small noise strength. At moderate and large noise, a local order parameter at the onset of the critical phase emerges.