875 research outputs found
Entanglement Entropy in 2D Non-abelian Pure Gauge Theory
We compute the Entanglement Entropy (EE) of a bipartition in 2D pure
non-abelian gauge theory. We obtain a general expression for EE on an
arbitrary Riemann surface. We find that due to area-preserving diffeomorphism
symmetry EE does not depend on the size of the subsystem, but only on the
number of disjoint intervals defining the bipartition. In the strong coupling
limit on a torus we find that the scaling of the EE at small temperature is
given by ,
which is similar to the scaling for the matter fields recently derived in
literature. In the large limit we compute all of the Renyi entropies and
identify the Douglas-Kazakov phase transition.Comment: 6 page
Divide and conquer: resonance induced by competitive interactions
We study an Ising model in a network with disorder induced by the presence of
both attractive and repulsive links. This system is subjected to a subthreshold
signal, and the goal is to see how the response is enhanced for a given
fraction of repulsive links. This can model a network of spin-like neurons with
excitatory and inhibitory couplings. By means of numerical simulations and
analytical calculations we find that there is an optimal probability, such that
the coherent response is maximal
Bulk-Edge correspondence of entanglement spectrum in 2D spin ground states
General local spin ground states, described by a Valence Bond Solid (VBS)
on a two dimensional lattice are studied. The norm of these ground states is
mapped to a classical O(3) model on the same lattice. Using this
quantum-to-classical mapping we obtain the partial density matrix
associated with a subsystem of the original ground state. We show that
the entanglement spectrum of in a translation invariant lattice
is given by the spectrum of a quantum spin chain at the boundary of region ,
with local Heisenberg type interactions between spin 1/2 particles.Comment: 8 pages, 4 figures, one section and references adde
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