Evolution of entanglement in non Markovian channels

Anahita Motavallibashi, Hamidreza Mohammadi, Ahmad Akhound

Quantum teleportation of the quantum correlated states via noisy channels is investigated. The noisy channels are realized by a couple of two-level atoms (qubits) embedded in a zero-temperature bosonic bath. The entanglement of the channels is provided by the interqubit interaction and/or through the memory of the environment. Especially for the case of noninteracting qubits, the resource of the teleportation can be supplied by the entangled state of the channel, which is provided by information backflow in the non-Markovian regime of the evolution. More non-Markovianity of the dynamics generates a higher amount of induced entanglement and hence enhances the quality of the quantum correlation teleportation process. When the degree of non-Markovianity of dynamics is sufficiently high, quantum teleportation, which is superior to classical communication, is achievable.

Ting Yu, Joseph H. Eberly

Shi‐Dong Liang

Himadri Shekhar Dhar, Manabendra Nath Bera, Gerardo Adesso

Non-Markovian evolution in open quantum systems is often characterized in terms of the backflow of information from environment to system and is thus an important facet in investigating the performance and robustness of quantum information protocols. In this work, we explore non-Markovianity through the breakdown of monotonicity of a metrological figure of merit, called the quantum interferometric power, which is based on the minimal quantum Fisher information obtained by local unitary evolution of one part of the system, and can be interpreted as a quantifier of quantum correlations beyond entanglement. We investigate our proposed non-Markovianity indicator in two relevant examples. First, we consider the action of a single-party dephasing channel on a maximally entangled two-qubit state, by applying the Jamio\l{}kowski-Choi isomorphism. We observe that the proposed measure is consistent with established non-Markovianity quantifiers defined using other approaches based on dynamical divisibility, distinguishability, and breakdown of monotonicity for the quantum mutual information. Further, we consider the dynamics of two-qubit Werner states, under the action of a local, single-party amplitude damping channel, and observe that the nonmonotonic evolution of the quantum interferometric power is more robust than the corresponding one for entanglement in capturing the backflow of quantum information associated with the non-Markovian process. Implications for the role of non-Markovianity in quantum metrology and possible extensions to continuous variable systems are discussed.

Yongmei Liu, Yinghua Ji

Zi-Long Fan, Yu-Kun Ren, Hao‐Sheng Zeng

We present a paradigmatic method for exactly studying non-Markovian dynamics of a multi-level V-type atom interacting with a zero-temperature bosonic bath. Special attention is paid to the entanglement evolution and the dynamical non-Markovianity of a three-level V-type atom. We find that the entanglement negativity decays faster and non-Markovianity is smaller in the resonance regions than those in the non-resonance regions. More importantly, the quantum interference between the dynamical non-Markovianities induced by different transition channels is manifested, and the frequency domains for constructive and destructive interferences are found.