23,432 research outputs found
Phase diagram of a 2D Ising model within a nonextensive approach
In this work we report Monte Carlo simulations of a 2D Ising model, in which
the statistics of the Metropolis algorithm is replaced by the nonextensive one.
We compute the magnetization and show that phase transitions are present for
. A phase diagram (critical temperature vs. the entropic
parameter ) is built and exhibits some interesting features, such as phases
which are governed by the value of the entropic index . It is shown that
such phases favors some energy levels of magnetization states. It is also
showed that the contribution of the Tsallis cutoff is essential to the
existence of phase transitions
Experimental Determination of Thermal Entanglement in Spin Clusters using Magnetic Susceptibility Measurements
The present work reports an experimental observation of thermal entanglement
in a clusterized spin chain formed in the compound NaCuSiO.
The presence of entanglement was investigated through two measured quantities,
an Entanglement Witness and the Entanglement of Formation, both derived from
the magnetic susceptibility. It was found that pairwise entanglement exists
below K. Tripartite entanglement was also observed below K. A theoretical study of entanglement evolution as a function of applied
field and temperature is also presented.Comment: Submited to Phys. Rev.
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