We study a XY model which consists of a spin chain coupled to heat baths. We give a repeated quantum interaction Hamiltonian describing this model. We compute the explicit form of the associated Lindblad generator in the case of the spin chain coupled to one, two and several heat baths. We further study the properties of quantum master equation such as approach to equilibrium, local equilibrium...

We derive the asymptotic Bethe ansatz (AFS equations [1]) for the string on S ×R sector of AdS5 ×S5 from the integrable nonhomogeneous dynamical spin chain for the string sigma model proposed in [2]. It is clear from the derivation that AFS equations can be viewed only as an effective model describing a certain regime of a more fundamental inhomogeneous spin chain. Membre de l’Institut Universi...

Generalizing the mapping between the Potts model with nearest neighbour interaction and the six vertex model, we build a family of " fused Potts models " related to the spin k/2 Uqsu(2) invariant vertex model and quantum spin chain. These Potts models have still variables taking values 1,. .. , Q (√ Q = q + q −1) but they have a set of complicated multi spin interactions. The general technique ...

Recently it was established that a certain integrable long-range spin chain describes the dilatation operator of N = 4 gauge theory in the su(2) sector to at least three-loop order, while exhibiting BMN scaling to all orders in perturbation theory. Here we identify this spin chain as an approximation to an integrable short-rangedmodel of strongly correlated electrons: The Hubbard model.

We study the equations for the quasi-momenta which characterize the wave-functions in the Bethe ansatz for the XXX-Heisenberg model. We show in a simple analytical fashion, that the usual " string hypothesis " incorrectly predicts the number of real solutions and the 1

The N site open XXZ quantum spin chain with a right non-diagonal boundary and special diagonal left boundary is considered. The boundary non-local charges originally obtained from a field theoretical viewpoint, for the sine Gordon model on the half line, are recovered from the spin chain point of view. Furthermore, the symmetry of the open spin chain is exhibited. More specifically, we show tha...

We discuss the origin of an enigmatic low-temperature behavior some one-dimensional decorated spin systems which was coined pseudo-transition. Tracing out parts results in standard Ising-chain model with temperature-dependent parameters and unexpected thermodynamic quantities correlations chains can be tracked down critical point at H=0 T=0. illustrate this perspective using as examples spin-1/...

We calculate the local correlation functions of charge and spin for the one-chain and two-chain Hubbard model using the density matrix renormalization group method and the recursion technique. Keeping only finite number of states we get good accuracy for the low energy excitations. We study the charge and spin gaps, bandwidths and weights of the spectra for various values of the on-site Coulomb...