arXiv subjects

H. Caldas

Publications and source records attributed to H. Caldas.

4 recordsLinked to original sources

arXiv2025

Saturation Field as a Direct Probe of Exchange and Single-Ion Anisotropies in Spin-1 Magnets

High magnetic fields provide a direct route to probe the anisotropies that govern spin dynamics in layered magnets. Using the SU(3) bond operator framework for spin 1 systems, we derive analytic expressions for the magnon spectrum and the critical fields delimiting the field induced ordered phase. We show that the upper critical field $h_{c2}$ carries a simple and quantitative fingerprint of both exchange anisotropy and single ion symmetry breaking, enabling high field experiments to serve as sensitive probes of microscopic anisotropy. We further map how these anisotropies, together with interlayer coupling, control the extent and location of the magnon Bose Einstein condensation dome. Our results provide experimentally accessible criteria for identifying symmetry breaking mechanisms in real spin 1 materials.

cond-mat.str-el↗

arXiv2023

The Schwinger and Chiral Schwinger Models in a Non-perturbative Spectral Regularization

We investigate the employment of a non-perturbative regularization scheme -- the spectral regularization, which is based on the gauge technique, previously implemented in the context of chiral quark models -- in the study of the gauge symmetry preservation within the Schwinger model and violation in the chiral Schwinger model. We show that the spectral regularization provides mathematical consistent and ambiguity free solutions for the two-point functions of both Schwinger and chiral Schwinger models in exact (1+1) dimensions, correctly displaying the gauge invariance in the Schwinger model and the axial anomaly in the chiral Schwinger model. The employment of the spectral regularization avoids any dependence on ambiguous amplitudes and/or unconventional $\gamma^5$ algebra. Our results reinforce the strength of the spectral regularization as a mathematical consistent, divergence free, and ambiguity free regularization scheme that correctly implements symmetry conservation or violation in each case.

hep-th↗

arXiv2020

Effects of anisotropic correlations in fermionic zero-energy bound states of topological phases

Topological phases of matter have been used as a fertile realm of intensive discussions about fermionic fractionalization. In this work, we study the effects of anisotropic superconducting correlations in the fermionic fractionalization on the topological phases. We consider a hybrid version of the SSH and Kitaev models with an anisotropic superconducting order parameter to investigate the unusual states with zero energy that emerges in a finite chain. To obtain these zero energy solutions, we built a chain with a well-defined domain wall at the middle of the chain. Our solutions indicate an interesting dynamic between the zero-energy state around the domain wall and the superconducting correlation parameters. Finally, we find that the presence of an isolated Majorana at the ends of the chain is strongly dependent on the existence of the solitonic excitation at the middle of the chain.

cond-mat.mes-hall↗

arXiv2015

Influence of Induced Interactions on Superfluid Properties of Quasi-Two Dimensional Dilute Fermi Gases With Spin-Orbit Coupling

We study the effects of induced interactions on the pairing gap, transition temperature and chemical potential of a quasi-two dimensional Fermi gas of atoms with spin-orbit coupling. We find that these mean-field parameters are significantly modified when induced interactions are taken into account. We also investigate the implications of induced interactions corrections for the BCS-BEC crossover driven by spin-orbit coupling, that happens even for small (compared to the Fermi energy) values of the binding energy.

cond-mat.quant-gas↗