Emergence of the pointer basis through the dynamics of correlations

We use the classical correlation between a quantum system being measured and its measurement apparatus to analyze the amount of information being retrieved in a quantum measurement process. Accounting for decoherence of the apparatus, we show that these correlations may have a sudden transition from a decay regime to a constant level. This transition characterizes a non-asymptotic emergence of the pointer basis, while the system-apparatus can still be quantum correlated. We provide a formalization of the concept of emergence of a pointer basis in an apparatus subject to decoherence. This contrast of the pointer basis emergence to the quantum to classical transition is demonstrated in an experiment with polarization entangled photon pairs.Comment: 4+2 pgs, 3 figures. Title changed. Revised version to appear on PR

Quantum quench in the infinitely repulsive Hubbard model: The stationary state

We use the quench action approach to study the non-equilibrium dynamics after a quantum quench in the Hubbard model in the limit of infinite interaction. We identify a variety of low-entangled initial states for which we can directly compute the overlaps with the Hamiltonian's eigenstates. For these initial states, we analytically find the rapidity distributions of the stationary state characterising the expectation values of all local observables. Some of the initial states considered are not reflection symmetric and lead to non-symmetric rapidity distributions. To study such cases, we have to introduce a generalised form for the reduced entropy which measures the entropy restricted to states with non-zero overlap. The initial states considered are of direct experimental realisability and also represent ideal candidates for studying non-equilibrium dynamics in the Hubbard model for finite interactions

Prediction of the edaphic factors influence upon the copper and cobalt accumulation in two metallophytes using copper and cobalt speciation in soils.

Background and aims: Among the unique flora on copper and cobalt rich soils, some species are able to hyperaccumulate the Cu and Co in their shoots, however, the unexplained high variations of Cu and Co concentrations in shoots have been highlighted. A good comprehension of the Cu and Co accumulation variations would go through a characterization of the Cu and Co speciation in soils. We examined the covariations of Cu and Co speciation in soils and Cu and Co concentrations in plants. Methods: Plant samples of two species and soil samples (n = 146) were collected in seven pedogeochemically contrasted sites. Cu and Co speciation in soils was modeled by WHAM 6.0. Results: Variation in copper accumulation in plant shoots were mostly influenced by Cu adsorbed by the Mn and Fe oxides fractions, whereas Co accumulation variations were strongly influenced by Co free and Co adsorbed by the OM and Fe fractions. Conclusions: Availability of Cu and Co seems to be species-specific and is not explained only by the free Cu and Co content in the soil solution, but also strongly by the part linked to colloidal fractions. Availability of Cu and Co is a complex mechanism, closely related to all the biogeochemical processes which occur in the rhizosphere. Future work should perform experiments in controlled conditions to examine the soil parameters that influence the Cu and Co availability. © 2014 Springer International Publishing Switzerland.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Exact solution for the quench dynamics of a nested integrable system

Integrable models provide an exact description for a wide variety of physical phenomena. For example nested integrable systems contain different species of interacting particles with a rich phenomenology in their collective behavior, which is the origin of the unconventional phenomenon of spin-charge separation. So far, however, most of the theoretical work in the study of non-equilibrium dynamics of integrable systems has focussed on models with an elementary (i.e. not nested) Bethe ansatz. In this work we explicitly investigate quantum quenches in nested integrable systems, by generalizing the application of the quench action approach. Specifically, we consider the spin-1 Lai-Sutherland model, described, in the thermodynamic limit, by the theory of two different species of Bethe-ansatz particles, each one forming an infinite number of bound states. We focus on the situation where the quench dynamics starts from a simple matrix product state for which the overlaps with the eigenstates of the Hamiltonian are known. We fully characterize the post-quench steady state and perform several consistency checks for the validity of our results. Finally, we provide predictions for the propagation of entanglement and mutual information after the quench, which can be used as signature of the quasi-particle content of the model