Dzyaloshinskii-Moriya相互作用对量子XY链中热纠缠的影响

摘要

The effects of Dzyaloshinskii-Moriya ( DM ) interaction on the thermal entanglement of mixed-spin XY chain ( 1/2,3/2) and spin 1 XY chain are investigated through negativity.By calculating the entanglement between two particles, it was found that the DM interaction can not only increase the entanglement, but also make the entanglement of the particles reach a stationary value.The higher the temperature, the greater the DM interaction is required to make the thermal entanglement arrive at this stationary value.Under the same condition, the entanglement between two spin 1 particles is less than that between mixed-spin.The exchange-coupling interactions between the spins are helpful to strengthen the thermal entanglement, hence the exchange-coupling can be used to modulate the entanglement along with the DM interaction.When the exchange-coupling interaction is small, one can enlarge the DM interaction to increase the entanglement, whereas, when the DM interaction is small, one can increase the thermal entanglement through increasing the exchange-coupling interaction.%研究了Dzyaloshinskii-Moriya(DM)相互作用对混合自旋(1/2,3/2)XY链以及自旋为1的XY链热纠缠的影响.通过计算两粒子之间的纠缠,发现它不仅能够增强纠缠,而且能使两粒子之间的纠缠度达到一稳定值;当温度较高时,要使热纠缠达到稳定值需要更强的这种相互作用.在相同的条件下,自旋s=1的两粒子之间的纠缠要小于混合自旋两粒子之间的纠缠.粒子之间的交换耦合相互作用有助于加强粒子之间的热纠缠,因此可以与DM相互作用一起调节纠缠度.当交换耦合相互作用比较小时,可以通过加强这种相互作用来提高系统的纠缠度;当DM相互作用比较小时,可以通过加大交换耦合相互作用来提高纠缠度.