Meissner mechanism for the spin supercurrent and influence of the critical behavior on spin transport in the frustrated Heisenberg model

Joint Event on 3^rd International Conference on Nuclear and Plasma Physics & 4^th International Conference on Quantum Physics and Quantum Technology

November 05-06, 2018 | London, UK

Leonardo S Lima

CEFET-MG, Brazil

Scientific Tracks Abstracts: J Astrophys Aerospace Technol

Abstract :

The local spontaneous symmetry breaking is a general phenomena in condensed matter physics. It is characterized by the fact that the action has a local symmetry but the quantum theory instead of having a unique vacuum state which respects this symmetry, has a family of degenerate vacua that transform into each other under the action of the symmetry group. A simple example is given by a ferromagnetic model in which the action governing its microscopic dynamics is invariant under spatial rotations. A kind of local gauge invariance or spontaneous breaking of U(1) gauge symmetry is realized in nature in the phenomenon of superconductivity. We have proposed the Meissner mechanism for the spin supercurrent in quantum spin systems. Besides, we study the behavior of the AC spin conductivity in neighbourhood of quantum phase transition in a frustrated spin model such as the antiferromagnet in the union jack lattice with single ion anisotropy at T=0. We investigate the spin conductivity for this model that presents exchange interactions J1 and J2. Our results show a single peak for the conductivity with the height varying with the behavior of critical anisotropy DC with J2. We obtain the conductivity tending to zero in the limit 0. Recent Publications 1. L S Lima (2016) Influence of quantum phase transition on spin conductivity in the anisotropic three-dimensional ferromagnetic model. Solid State Commun. 250C:49. 2. L S Lima A S T Pires and B V Costa (2015) Critical behaviour of the site diluted quantum anisotropic Heisenberg model in two dimensions. Physica A: Statistical Mechanics and its Applications. 438(C):579-585. 3. L S Lima (2017) Spin transport of the frustrated quasi-two dimensional XY-like antiferromagnet. J. Magn. Magn. Mater. 422(C):412. 4. L S Lima (2018) Spin current and effect of quantum phase transition in the two-dimensional XY model. Physica C: Superconductivity and its applications. 547:22-26.

Biography :

Leonardo S Lima pursued his PhD from Federal University of Minas Gerais, Brazil; Postdoctoral studies from TU Kaiserslautern, Germany. He is the currently Professor of Physics in the Department of Physics and Mathematics at the Federal Center for Technological Education of Minas Gerais (CEFET-MG). He has more than 50 papers published in international journal and indexed.

E-mail: lslima7@yahoo.com.br