Non-Markovian entanglement dynamics of noisy continuous-variable quantum channels

Abstract

We investigate the entanglement dynamics of continuous-variable quantum channels in terms of an entangled squeezed state of two cavity fields in a general non-Markovian environment. Using the Feynman-Vernon influence functional theory in the coherent-state representation, we derive an exact master equation with time-dependent coefficients reflecting the non-Markovian influence of the environment. The influence of environments with different spectral densities, e.g., Ohmic, subOhmic, and super-Ohmic, is numerically studied. The non-Markovian process shows its remarkable influences on the entanglement dynamics due to the sensitive time-dependence of the dissipation and noise functions within the typical time scale of the environment. The Ohmic environment shows a weak dissipation-noise effect on the entanglement dynamics, while the sub-Ohmic and super-Ohmic environments induce much more severe noise. In particular, the memory of the system interacting with the environment contributes a strong decoherence effect to the entanglement dynamics in the super-Ohmic case.

Non-Markovian dynamics of an open quantum system with initial system-reservoir correlations: A nanocavity coupled to a coupled-resonator optical waveguide

“…In the literature, exact master equations for open systems are mostly derived without initial correlations, such as the systems associated with quantum Brown motions [7][8][9], quantum dot systems in various nanostructures [13,14], and cavity systems coupled to structured reservoirs as well as general non-Markovian reservoirs [16,17,36]. Here we concentrate the exact master equation for the photonic system in the presence of initial Gaussian correlated states.…”

Non-Markovian dynamics of quantum open systems embedded in a hybrid environment

“…By assuming all the terms associated with noises are zero [45], the zeroth order O (0) and Q (0) operators can be obtained from Eqs. (18)(19) as…”

“…Although a realistic environment can be very complicated, it is typically composed of bosons and fermions. For a bosonic bath, a set of powerful tools have been developed to investigate the open system dynamics, such as path integral approach [18,19], master equation approach [20,21,22,23], and Markov and non-Markovian quantum trajectory approach [24,25,26,27,28]. For fermionic bath, similar tools have also been developed, including scattering theory [29], non-equilibrium Green's function approach [30], and fermionic path integral [31,32].…”

Quantum nonunital dynamics of spin-bath-assisted Fisher information

“…3 Indeed, actual interactions between quantum systems and environments generally give rise to one non-Markovian dynamics. 2 The revivals of polarization parameters, 4 quantum correlations, 5 quantum entanglement 6 and quantum Fisher information 7,8 can happen in the non-Markovian decoherence channel. Much more works have been presented in order to help people to understand non-Markovian dynamical processes.…”