title: Entanglement spectra of quantum Heisenberg ladders.
abstract: Bipartite entanglement measures are surprisingly useful tools to investigate quantum phases of correlated electrons. Here, I analyze the entanglement spectrum of gapped two-leg quantum Heisenberg ladders on a periodic ribbon partitioned into two identical periodic chains. The entanglement spectrum closely reflects the low-energy gapless spectrum of each individual edge. This extends the conjecture initially drawn for fractional quantum Hall systems to the field of quantum magnetism, stating a direct correspondence between the low-energy entanglement spectrum of a partitioned system and the true spectrum of the virtual edges. A mapping of the reduced density matrix to a thermodynamic density matrix is also proposed via the introduction of an effective temperature.
authors.affiliation: Laboratoire de Physique Théorique UMR5152, CNRS and Université de Toulouse, F-31062 France.
authors.forename: Didier
authors.initials: D
authors.lastname: Poilblanc