Thermal entanglement of the Ising Heisenberg diamond chain with Dzyaloshinskii Moriya interaction  

作　　者：谯洁 周斌 

机构地区：[1]Department of Physics, Hubei University

出　　处：《Chinese Physics B》2015年第11期110-117,共8页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.11274102);the New Century Excellent Talents in University of Ministry of Education of China(Grant No.NCET-11-0960);the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20134208110001)

摘　　要：We investigate the thermal entanglement in a spin-l/2 Ising-Heisenberg diamond chain, in which the vertical Heisen- berg spin dimers alternate with single Ising spins. Due to the fact that the Dzyaloshinskii-Moriya （DM） interaction con- tributes to unusual and interesting magnetic properties in actual materials, and moreover it plays a significant role in the degree of the entanglement of the Heisenberg quantum spin systems, we focus on the effects of different DM interactions, including Dz and Dx, on the thermal entanglement of the Heisenberg spin dimer. The concurrence, as a measure of spin dimer entanglement, is calculated for different values of exchange interactions, DM interaction, external magnetic field, and temperature. It is found that the critical temperature and the critical magnetic field corresponding to the vanishing of entanglement increase with DM interaction, and the entanglement revival region gets larger by increasing DM interac- tion, thus DM interaction favors the formation of the thermal entanglement. It is observed that different DM interaction parameters （Dz and Dx） have remarkably different influences on the entanglement. Different from the case Dz, there is the non-monotonic variation of the concurrence with temperature in the case Dx, and additionally the DM interaction Dx can induce the entanglement near zero temperature in the case that the antiferromagnetic Ising-type interaction constant is larger than the antiferromagnetic Heisenberg interaction constant. It is also shown that for the same value of DM interaction the critical magnetic field of the case Dx is larger than that of the case Dz.We investigate the thermal entanglement in a spin-l/2 Ising-Heisenberg diamond chain, in which the vertical Heisen- berg spin dimers alternate with single Ising spins. Due to the fact that the Dzyaloshinskii-Moriya （DM） interaction con- tributes to unusual and interesting magnetic properties in actual materials, and moreover it plays a significant role in the degree of the entanglement of the Heisenberg quantum spin systems, we focus on the effects of different DM interactions, including Dz and Dx, on the thermal entanglement of the Heisenberg spin dimer. The concurrence, as a measure of spin dimer entanglement, is calculated for different values of exchange interactions, DM interaction, external magnetic field, and temperature. It is found that the critical temperature and the critical magnetic field corresponding to the vanishing of entanglement increase with DM interaction, and the entanglement revival region gets larger by increasing DM interac- tion, thus DM interaction favors the formation of the thermal entanglement. It is observed that different DM interaction parameters （Dz and Dx） have remarkably different influences on the entanglement. Different from the case Dz, there is the non-monotonic variation of the concurrence with temperature in the case Dx, and additionally the DM interaction Dx can induce the entanglement near zero temperature in the case that the antiferromagnetic Ising-type interaction constant is larger than the antiferromagnetic Heisenberg interaction constant. It is also shown that for the same value of DM interaction the critical magnetic field of the case Dx is larger than that of the case Dz.

关 键 词：thermal entanglement Ising-Heisenberg diamond chain Dzyaloshinskii-Moriya interaction 

分 类 号：O413.1[理学—理论物理]