Sudden death of entanglement induced by a minimal thermal environment

OPTICS COMMUNICATIONS

卷:475

Article

Decordi, G. L.¹  Vidiella-Barranco, A.¹ 

[1] Univ Campinas UNICAMP, Gleb Wataghin Inst Phys, BR-13083859 Campinas, SP, Brazil

关键词: Coupled qubits;    Thermal noise;    Entanglement sudden death;    Decoherence;   

DOI  :  10.1016/j.optcom.2020.126233

来源: Elsevier

【 摘 要 】

We study the dynamics of two interacting two-level systems (qubits) having one of them isolated and the other coupled to a single mode electromagnetic field in a thermal state. The field plays the role of a small environment, in contrast to the usual approach of modelling an environment via a thermal reservoir with many degrees of freedom. We find the analytical solution of the proposed model, which allows us to investigate the consequences of the coupling to the small environment on characteristic quantum features of the two-qubit system. We study the time evolution of quantum entanglement and coherence, verifying the dependence on the relevant coupling constants as well as the influence of the effective temperature of the environment. Interestingly, we find that both sudden death and sudden birth of entanglement may occur in such a simple system. We also discuss a different partition, in which the isolated qubit is considered to be coupled to a composite environment, constituted by the other qubit plus the field mode.

【 授权许可】

Free