THE FINITE-SIZE EFFECT ON THE ENTANGLEMENT OF THE QUANTUM ISING CHAIN

2004 ◽  
Vol 18 (17n19) ◽  
pp. 2564-2568 ◽  
Author(s):  
LIFA ZHANG ◽  
PEIQING TONG
Keyword(s):  
Phase Transition ◽  
Quantum Phase Transition ◽  
Spin Chain ◽  
Transition Point ◽  
Nearest Neighbor ◽  
Finite Size ◽  
Phase Transition Point ◽  
Finite Size Effect ◽  
Ising Chain ◽  
Derivatives Of

By using the concurrence, the entanglement of a quantum Ising chain is studied numerically. It is found that there is a gap in the concurrence of the nearest-neighbor spins at the quantum phase transition point for the chain with even spins. The gap disappears as the number of the spins goes to infinite. Except for the critical point, the derivatives of the concurrence display the similar scaling behavior as that of the odd-spin chain.

Influence of the Size Effect on Magnetic Susceptibility in Ultrathin Films

2015 ◽  
Vol 233-234 ◽  
pp. 639-642
Author(s):  
Leonid L. Afremov ◽  
Aleksandr A. Petrov
Keyword(s):  
Experimental Data ◽  
Phase Transition ◽  
Magnetic Susceptibility ◽  
Theoretical Analysis ◽  
Ultrathin Films ◽  
Transition Point ◽  
Finite Size ◽  
Phase Transition Point ◽  
Shape Curve ◽  
Good Agreement

The magnetic susceptibility dependence on temperature near phase transition point was investigated by theoretical analysis. It is shown that with decreasing of the film thickness the magnetic susceptibility shape curve becomes more rounded finite-size function, centered about the lowered temperature Tc (L). The obtained results are in good agreement with experimental data.

scholarly journals Quantum discord and quantum phase transition in spin-1/2 frustrated Heisenberg chain

2013 ◽  
Vol 13 (5&6) ◽  
pp. 452-468
Author(s):  
Chu-Hui Fan ◽  
Heng-Na Xiong ◽  
Yixiao Huang ◽  
Zhe Sun
Keyword(s):  
Phase Transition ◽  
Quantum Phase Transition ◽  
Quantum Discord ◽  
Nearest Neighbor ◽  
Finite Size ◽  
Quantum Phase ◽  
Nonlinear Dependence ◽  
Heisenberg Chain ◽  
Transition Points ◽  
Analytical Result

By using the concept of the quantum discord (QD), we study the spin-1/2 antiferromagnetic Heisenberg chain with next-nearest-neighbor interaction. Due to the $SU(2)$ symmetry and $Z_{2}$ symmetry in this system, we obtain the analytical result of the QD and its geometric measure (GMQD), which is determined by the two-site correlators. For the 4-site and 6-site cases, the connection between GMQD (QD) and the eigenenergies was revealed. From the analytical and numerical results, we find GMQD (QD) is an effective tool in detecting the both the first-order and the infinite-order quantum-phase-transition points for the finite-size systems. Moreover, by using the entanglement excitation energy and a universal frustration measure we consider the frustration properties of the system and find a nonlinear dependence of the GMQD on the frustration.

scholarly journals Распространение поверхностной магнитоупругой волны в ферромагнетике в области ориентационного фазового перехода

2020 ◽  
Vol 62 (6) ◽  
pp. 851
Author(s):  
И.В. Мальцев ◽  
И.В. Бычков ◽  
Д.А. Кузьмин ◽  
В.Г. Шавров
Keyword(s):  
Phase Transition ◽  
Group Velocity ◽  
Yttrium Iron Garnet ◽  
Transition Point ◽  
Phase Transition Point ◽  
Yttrium Iron ◽  
Orientational Phase Transition ◽  
Velocity Changes ◽  
Iron Garnet ◽  
Magnetoelastic Surface

In this paper, we have studied the dependencies of group velocity and damping of magnetoelastic surface waves on the frequency at various external magnetic fields and propagation angles. The group velocity spikes occur at frequencies at which the damping peaks of the surface wave are detected. The behavior of a surface magnetoelastic wave in the vicinity of the orientational phase transition was also investigated. At the phase transition point, the group velocity changes by 1%. Dependences of the damping along the surface at various propagation angles point out on the nonreciprocal nature of the wave. All dependencies in this work were obtained using computer modeling. The parameters of the ferromagnet are taken typical for yttrium-iron garnet.

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