A study on composed nonextensive magnetic systems
authors Navarro, FAR; Reis, MS; Lenzi, EK; Oliveira, IS
nationality International
journal PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
author keywords manganites; non-extensive statistics; partial trace
keywords COLOSSAL MAGNETORESISTIVE MANGANITES; STATISTICAL-MECHANICS; EVIDENCES; BEHAVIOR
abstract We investigate the magnetic properties of a composed nonextensive system. The work is motivated by recent proposals that manganites are magnetically nonextensive objects, according to Tsallis statistics. We consider a two-parts composed system, A-B (both spins 1/2), and calculate 2 self-consistently the partial magnetizations in the mean field approximation, M-A and M-B, for the cases the coupling between the subsystems is either ferro or anti-ferromagnetic. This involves the notion of partial trace in the nonextensive statistics. For temperatures below the magnetic ordering temperatures, and q not equal 1, we found strong disagreement between the M vs. T curves calculated from the total 4 x 4 Hilbert space, through rho(q), when compared to the calculation made from the 2 x 2 subspaces, if we use the usual definition rho(A(B)) = Tr-B(A)(rho), and then elevates the matrices to the qth power, as adopted in other contexts in the literature of the nonextensive statistics. On another hand, full agreement is found if we take rho(A(B),q) = Tr-B(A)(rho(q)), remaining q an implicit parameter. (C) 2004 Elsevier B.V. All rights reserved.
publisher ELSEVIER SCIENCE BV
issn 0378-4371
year published 2004
volume 343
beginning page 499
ending page 504
digital object identifier (doi) 10.1016/j.physa.2004.05.074
web of science category Physics, Multidisciplinary
subject category Physics
unique article identifier WOS:000224495900034
  impact metrics
journal analysis (jcr 2019):
journal impact factor 2.924
5 year journal impact factor 2.625
category normalized journal impact factor percentile 70
dimensions (citation analysis):
altmetrics (social interaction):



 


Sponsors

1suponsers_list_ciceco.jpg