近日，俄罗斯莫斯科国立大学的N. S. Maslova与德国柏林洪堡大学的I. M. Sokolov等人合作并取得一项新进展。经过不懈努力，他们揭示耦合量子点中存在涨落时纠缠贝尔态的时间演化过程。相关研究成果已于2024年3月25日在国际知名学术期刊《物理评论A》上发表。

本文分析了耦合量子点(QDs)中存在涨落和相干电子跳跃的双量子比特纠缠贝尔态的动力学。研究人员利用Keldysh图解技术，得到了在不同初始条件下系统处于不同贝尔态的时变概率的显式表达式。研究结果表明，一对贝尔态的时间演化及其衰减速率与另一对贝尔态存在显著差异。这证实了一对贝尔态对波动的鲁棒性比另一对更强。

此外，研究人员还对不同初始条件下贝尔态的稳态占据情况进行了详细分析。 这些发现对于量子通信的安全性和量子信息处理等关键领域具有重要意义，特别是在那些需要长寿命贝尔态的应用中。

附：英文原文

Title: Time evolution of entangled Bell states in coupled quantum dots in the presence of fluctuations

Author: N. S. Maslova, V. N. Mantsevich, I. M. Sokolov, P. I. Arseyev

Issue&Volume: 2024/03/25

Abstract: We analyze the dynamics of two-qubit entangled Bell states in coupled quantum dots (QDs) in the presence of both fluctuations and coherent electron hopping between the dots. The explicit expression for time-dependent probability to find the system in the different Bell states was obtained for various initial conditions by means of Keldysh diagram technique. It was revealed that time evolution of one pair of Bell states and its decay rate strongly differs from another one. It was demonstrated that one pair of Bell states is more robust against fluctuations than another one. The stationary occupation of Bell states for different initial conditions was also analyzed. Obtained results are important for the problems where long-living Bell states are needed such as the security of quantum communication and quantum information processing.

DOI: 10.1103/PhysRevA.109.032430

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.109.032430