Quantum information in many-body physics (Dr. U. Marzolino)
- Date: Sep 7, 2016
- Time: 11:30 AM - 12:30 PM (Local Time Germany)
- Speaker: Dr. Ugo Marzolino, University of Ljubljana, Slovenia
- Room: Herbert-Walther-Hörsaal
- Host: MPQ, Theory Division
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.