System-reservoir dynamics of quantum and classical correlations

Abstract

We address the system-reservoir dynamics of classical and quantum correlations in the decoherence phenomenon, regarding a two qubit composite system interacting with two independent environments. The most common noise channels (amplitude damping, phase damping, bit flip, bit-phase flip, and phase flip) was studied. By analytical and numerical analysis we found that, contrary to what is usually stated in the literature, decoherence may occurs without entanglement between the system and the environment. We also found that, in some cases, the bipartite quantum correlation initially presented in the system is completely evaporated, it is not transferred to the environments.Comment: To appear in PR

Sudden change in quantum and classical correlations and the Unruh effect

“…Equation (11) gives a measure of the total correlations (including the quantum and the classical ones) contained in a bipartite quantum system [9,10,41,42]. The classical part of correlation (11) can be expressed as being the "maximum classical mutual information" obtained by local measurements on both partitions of a composite state [6]:…”

“…Recent results showing that almost all (separable) quantum states actually have such nonclassical correlations [3] and that they can improve some computational tasks in comparison to when classical states are used [4,5] reinforce the relevance of such an issue. As a result, the last few years have witnessed an increasing number of articles discussing the quantification of these correlations [1,2,[6][7][8], their behavior under decoherence [9][10][11][12], and their relevance for quantum phase transitions [13][14][15][16].…”

Revisiting Quantum Discord for Two-Qubit X States: The Error Bound to an Analytical Formula

“…The first reason is that the X state can be obtained through a unitary transformation to a two qubit state. The second one is that the general two qubit state can become a X state under a noisy channel [11]. Ali et.…”

System-environment dynamics of X-type states in noninertial frames

“…But fortunately, due to the density matrixes from (10) to (13) have X-type structures, here we have a simpler expression for the concurrence [33] C(ρ) = 2 max 0, figures. This is due to the fact that the environments E A and ER are symmetrical, thus the density matrix representing the bipartite subsystem AE A (a) is similar to that of the bipartite subsystemRER(a), and leading to a similar dynamic.…”

“…From Eq. (6) we find that the action of the amplitude damping channel over one qubit can be represented by the following phenomenological map [33] …”