Correlated coherent states

A. D. Jannussis, G. Karayannis, Παναγιώτης Παναγόπουλος +1 more

Zhihua Guo, Huaixin Cao

Abstract Quantum coherence and quantum correlation are two fundamental resources in quantum information and computation. Quantum correlated states in a bipartite system are the same as the states that are coherent with respect to any product basis, while a coherent state with respect to some given product basis may not be quantum correlated. In this work, we focus on the question of creating quantum correlation from a coherent state via incoherent quantum operations. We compare characterizations of incoherent operations (IOs), maximally incoherent operations, genuinely incoherent operations and coherence-breaking operations and then explicit interrelations among these operations. Moreover, we give the specific forms of states in two-qubit systems, called super-coherent ones, that can be mapped to quantum correlated ones via some genuinely incoherent operation. We find that there exist some coherent states that are not super-coherent. Furthermore, we prove that a state can be mapped to a quantum correlated state via an incoherent operation if and only if it is coherent. Lastly, we prove that any maximally entangled state can be mapped to an incoherent one via some one-side coherence-breaking operation.

Thalanayar S. Santhanam

Alexander D. Sukhanov, O. N. Golubjeva, V. G. Baryakhtar

In this paper, we show that correlated coherent states (CCSs) are the most adequate candidates for the role of quantum analogues of the thermal states. The main result of our study reduces to the fact that quantum thermal effects under conditions of the equilibrium of an object with the stochastic environment at any temperatures can be explained consistently only on the basis of the set of CCSs.

L. Jebli, Mohammed Daoud A

Abstract In this paper, we investigate quantum correlations in coherent entangled states with photons added, which are produced by the creation operator acting on Bell entangled coherent states. The non-classical characteristics of the quantum state created by combining two-mode coherent states with any number of photons are also taken into account. We provide explicit expressions fort he pairwise quantum correlations found in superpositions of coherent states with (m; n)-photon addition. A comparison between a non-commutativity discord-like measure and the evaluation of the local quantum uncertainty to measure quantum correlations is also produced. We consider some special superpositions of quasi-Bell entangled coherent photon-added states to be illustrative of our analytical findings. Additionally, investigated is the quantum correlations' evolution in a channel that is dephasing.

S. Twareque Ali, Jean-Pierre Antoine, Jean‐Pierre Gazeau