CaceresVasquez, J., Jara, D. H., Costamagna, J., MartinezGomez, F., Silva, C. P., Lemus, L., et al. (2023). Effect of noncovalent selfdimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes. RSC Advances, 13(2), 825–838.
Abstract: A series of six new Cu(i) complexes with ([Cu(N{4R}pyridine2ylmethanimine)(PPh3)Br]) formulation, where R corresponds to a donor or acceptor psubstituent, have been synthesized and were used to study selfassociation effects on their structural and electrochemical properties. Xray diffraction results showed that in all complexes the packing is organized from a dimer generated by supramolecular pi stacking and hydrogen bonding. H1NMR experiments at several concentrations showed that all complexes undergo a fastselfassociation monomerdimer equilibrium in solution, while changes in resonance frequency towards the high or low field in specific protons of the imine ligand allow establishing that dimers have similar structures to those found in the crystal. The thermodynamic parameters for this selfassociation process were calculated from dimerization constants determined by VTH1NMR experiments for several concentrations at different temperatures. The values for KD (4.0 to 70.0 M1 range), Delta H (1.4 to 2.6 kcal mol(1) range), Delta S (0.2 to 2.1 cal mol(1) K1 range), and Delta G(298) (0.8 to 2.0 kcal mol(1) range) are of the same order and indicate that the selfdimerization process is enthalpically driven for all complexes. The electrochemical profile of the complexes shows two redox Cu(ii)/Cu(i) processes whose relative intensities are sensitive to concentration changes, indicating that both species are in chemical equilibrium, with the monomer and the dimer having different electrochemical characteristics. We associate this behaviour with the structural lability of the Cu(i) centre that allows the monomeric molecules to reorder conformationally to achieve a more adequate assembly in the noncovalent dimer. As expected, structural properties in the solid and in solution, as well as their electrochemical properties, are not correlated with the electronic parameters usually used to evaluate R substituent effects. This confirms that the properties of the Cu(i) complexes are usually more influenced by steric effects than by the inductive effects of substituents of the ligands. In fact, the results obtained showed the importance of noncovalent inte

Mellado, P. (2022). Topological edge states in dipolar zigzag stripes. J. Phys. Materials, 5(3), 034007.
Abstract: We study the magnon spectrum of stacked zigzag chains of point magnetic dipoles with an easy axis. The anisotropy due to the dipolar interactions and the twopoint basis of the zigzag chain unit cell combine to give rise to topologically nontrivial magnon bands in 2D zigzag lattices. Adjusting the distance between the two sublattice sites in the unit cell causes a band touching, which triggers the exchange of the Chern numbers of volume bands switching the sign of the thermal conductivity and the sense of motion of edges modes in zigzag stripes. We show that these topological features survive when the range of the dipolar interactions is truncated up to the second nearest neighbors.

MoyaCessa, H. M., Asenjo, F. A., Hojman, S. A., & SotoEguibar, F. (2022). Twomode squeezed state generation using the Bohm potential. Mod. Phys. Lett. B, 36(09), 2250025.
Abstract: We show that twomode squeezed vacuumlike states may be engineered in the BohmMadelung formalism by adequately choosing the phase of the wave function. The difference between our wave function and the one of the squeezed vacuum states is given precisely by the phase we selected. We would like to stress that the engineering of twomode vacuum states is possible due to the existence of the Bohm potential, and it is relevant because of its potential use in the propagation of optical fields, where it may render a variety of applications in optics. The approach to generate nonclassical states, namely, twomode squeezed states of a quantum mechanical system is one of the first applications of the MadelungBohm formalism.

SotoEguibar, F., Asenjo, F. A., Hojman, S. A., & MoyaCessa, H. M. (2021). Bohm potential for the time dependent harmonic oscillator. J. Math. Phys., 62(12), 122103.
Abstract: In the MadelungBohm approach to quantum mechanics, we consider a time dependent phase that depends quadratically on position, and we show that it leads to a Bohm potential that corresponds to a time dependent harmonic oscillator, provided the time dependent term in the phase obeys an Ermakov equation.

VidalSilva, N., & Troncoso, R. E. (2022). Timedependent straintuned topological magnon phase transition. Phys. Rev. B, 106(22), 224401.
Abstract: ollinear magnets in honeycomb lattices under the action of timedependent strains are investigated. Given the limits of highfrequency periodically varying deformations, we derive an effective Floquet theory for spin systems that results in the emergence of a spin chirality. We find that the coupling between magnons and spin chirality depends on the details of the strain such as the spatial dependence and applied direction. Magnonic fluctuations about the ferromagnetic state are determined, and it is found that spatially homogeneous strains drive the magnon system into topologically protected phases. In particular, we show that certain uniform strain fields play the role of an outofplane nearestneighbor DzyaloshinskiiMoriya interaction. Furthermore, we explore the application of nonuniform strains, which lead to a confinement of magnon states that for uniaxial strains propagates along the direction that preserves translational symmetry. Our work demonstrates a direct way in which to manipulate the magnon spectrum based on timedependent strain engineering that is relevant for exploring topological transitions in quantum magnonics.
