物理学报Issue(8)：1-10,10.DOI:10.7498/aps.64.080302
Dzyaloshinskii-Moriya相互作用和内禀消相干对基于两量子比特Heisenb erg自旋系统的量子密集编码的影响∗
Effects of Dzyaloshinskii-Moriya interaction and intrinsic decoherence on quantum dense co ding via a two-qubit Heisenb erg spin system
摘要
Abstract
By solving the Milburn equation, we investigate the properties of optimal channel capacity for the quantum dense coding via a two-qubit Heisenberg spin system with Dzyaloshinskii-Moriya (DM) interaction in the presence of intrinsic decoherence. The influences of different DM interactions, different initial states, anisotropic coupling parameters, and intrinsic decoherence on optimal coding capacity are analyzed in detail. It is found that the initial state of the system affects optimal coding capacity greatly, whose dependent parameters are not identical for different types of initial states. When the system is initially in the form of the nonmaximally entangled state c|01⟩+d|10⟩, a weak z-component DM interaction can enhance the value of optimal coding capacity as compared with the value without DM interaction, and the phase decoherence effect can suppress the oscillation of optimal coding capacity and make the capacity decrease to a stable value for the long-time evolution. It is also found that under the influence of intrinsic decoherence, the optimal transmission capacity of dense coding can keep an ideal maximal value of 2 by choosing the proper initial maximally entangled state. Moreover, no matter from which direction the DM interaction is introduced, the optimal coding capacity via the two-qubit Heisenberg spin system is always larger than the transmission capacity of any classical communication.关键词
Heisenberg模型/Dzyaloshinskii-Moriya相互作用/内禀消相干/最佳编码容量Key words
Heisenberg model/Dzyaloshinskii-Moriya interaction/intrinsic decoherence/optimal coding capacity引用本文复制引用
邹琴,胡小勉,刘金明..Dzyaloshinskii-Moriya相互作用和内禀消相干对基于两量子比特Heisenb erg自旋系统的量子密集编码的影响∗[J].物理学报,2015,(8):1-10,10.基金项目
国家自然科学基金(批准号:11174081,11034002,11134003,11104075)和国家重点基础研究发展计划(批准号:2011CB921602,2012CB821302)资助的课题.* Project supported by the National Natural Science Foundation of China (Grant Nos.11174081,11034002,11134003,11104075) and the National Basic Research Program of China (Grant Nos.2011CB921602,2012CB821302) （批准号:11174081,11034002,11134003,11104075）
