Self-calibrating tomography for multi-dimensional systems

We present a formalism for self-calibrating tomography of arbitrary dimensional systems. Self-calibrating quantum state tomography was first introduced in the context of qubits, and allows the reconstruction of the density matrix of an unknown quantum state despite incomplete knowledge of the unitary operations used to change the measurement basis. We show how this can be generalized to qudits, i.e. d-level systems, and provide a specific example for a V-type three-level atomic system whose transition dipole moments are not known. We show that it is always possible to retrieve the unknown state and process parameters, except for a set of zero measure in the state-parameter space.Comment: Revised version. 9 pages, 3 figure

XXIV Congreso Argentino de Hipertensión Arterial en Mendoza : abril de 2017

Fil: Renna, Nicolás F..Fil: Miatello, Roberto M.

Identification of Discolobium species indigenous to the Brazilian Pantanal ecosystem by microsatellite (SSRs) markers.

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Shear Modulus of an Elastic Solid under External Pressure as a function of Temperature: The case of Helium

The energy of a dislocation loop in a continuum elastic solid under pressure is considered within the framework of classical mechanics. For a circular loop, this is a function with a maximum at pressures that are well within reach of experimental conditions for solid helium suggesting, in this case, that dislocation loops can be generated by a pressure-assisted thermally activated process. It is also pointed out that pinned dislocations segments can alter the shear response of solid helium, by an amount consistent with current measurements, without any unpinning.Comment: 5 pages, 3 figure

One-dimensional dynamics of nearly unstable axisymmetric liquid bridges

A general one-dimensional model is considered that describes the dynamics of slender, axisymmetric, noncylindrical liquid bridges between two equal disks. Such model depends on two adjustable parameters and includes as particular cases the standard Lee and Cosserat models. For slender liquid bridges, the model provides sufficiently accurate results and involves much easier and faster calculations than the full three-dimensional model. In particular, viscous effects are easily accounted for. The one-dimensional model is used to derive a simple weakly nonlinear description of the dynamics near the instability limit. Small perturbations of marginal instability conditions are also considered that account for volume perturbations, nonequality of the supporting disks, and axial gravity. The analysis shows that the dynamics breaks the reflection symmetry on the midplane between the supporting disks. The weakly nonlinear evolution of the amplitude of the perturbation is given by a Duffing equation, whose coefficients are calculated in terms of the slenderness as a part of the analysis and exhibit a weak dependence on the adjustable parameters of the one-dimensional model. The amplitude equation is used to make quantitative predictions of both the (first stage of) breakage for unstable configurations and the (slow) dynamics for stable configurations

Long-term stability and reproducibility of magnetic colloids are key issues for steady values of specific power absorption over time

Virtually all clinical applications of magnetic nanoparticles (MNPs) require the formulation of biocompatible, water-based magnetic colloids. For magnetic hyperthermia, the requirements also include a high colloidal stability against precipitation and agglomeration of the constituent MNPs to maintain the heating efficiency of the ferrofluid in the long term. Agglomeration can change the heating efficiency by forming MNP clusters that modify the magnetic dipolar interactions between particles. Additionally, precipitation of the MNPs (i.e., the heating sources within the liquid) can change the measured heating rates of a colloid by altering the heat flow dynamics as the particles plunge to the precipitate. The specific power absorption (SPA) of single-domain MNPs depends critically on the average particle size and size distribution width and therefore first-rate reproducibility of different batches with respect to these parameters is also needed. We have studied the evolution of the SPA of highly reproducible and stable water-based colloids composed of polymer-coated Fe3O4 magnetic nanoparticles. By measuring the specific power absorption (SPA) values for 1 year as a function of field amplitude and frequency (H = 24 kA/m; 260 = f = 830 kHz), we have demonstrated that the SPA values of these samples can be reproduced in successive synthetic batches and stable for several months due to the in situ polymer coating that provides colloidal stability and keeps dipolar interactions negligible