CAJ | 학술논문

研究了伊辛模型中两个粒子在均匀和非均匀磁场中的热纠缠以及利用它作为量子信息传输的通道的传输保真度.计算出纠缠度的度量Concurrence,以及在不同种情况下呈现出来的纠缠度的表现形为.与均匀磁场相反,我们发现在非均匀磁场中传输的保真度能够得到增强,同时我们发现保真度还与耦合系数和温度有关.我们通过图形清楚地表示它们的性质,从图形中我们得出,第一:在其它条件相同的情况下,无论磁场方向是相同还是相反,它们的纠缠度都是相同的;但是当磁场方向相反时,平均保真度比均匀磁场具有更大的值.第二:为了提高纠缠和平均保真度我们可以通过选择适当的磁场强度、耦合系数和降低温度来实现.
연구료이신모형중량개입자재균균화비균균자장중적열규전이급이용타작위양자신식전수적통도적전수보진도.계산출규전도적도량Concurrence,이급재불동충정황하정현출래적규전도적표현형위.여균균자장상반,아문발현재비균균자장중전수적보진도능구득도증강,동시아문발현보진도환여우합계수화온도유관.아문통과도형청초지표시타문적성질,종도형중아문득출,제일:재기타조건상동적정황하,무론자장방향시상동환시상반,타문적규전도도시상동적;단시당자장방향상반시,평균보진도비균균자장구유경대적치.제이:위료제고규전화평균보진도아문가이통과선택괄당적자장강도、우합계수화강저온도래실현.
We investigate the thermal entanglement and average fidelity in the two-qubit Ising model with a uniform and nonuniform magnetic field. The concurrence of the measurement of entanglement is calculated. The behavior of concurrence is present at different forms. Contrary to the uniform magnetic fields case, the fidelity may be enhanced under a nonuniform magnetic field. And the average fidelity shows relation with the value of coupling constant J and Temperature T. We show them clearly by presenting figures. From the figures, two conclusions can be concluded.Firstly, in other same conditions, whether the magnetic field has the opposite or the same direction, the entangle-ment is the same. But when the magnetic field has the opposite direction, which can have a great effect on the aver-age fidelity of the teleportation. Secondly, to enhance the entanglement and average fidelity we should choose the proper value of B and coupling constant J and decrease the temperature T.