A procedure that allows us to obtain the dynamics of N independent bodies each locally interacting with its own reservoir is presented. It relies on knowledge single-body and it valid for any form environment noise. then applied study non-Markovian two qubits, a zero-temperature reservoir. shown that, although no interaction present or mediated between there revival their entanglement, after finite period time complete disappearance.

Knowledge of the dynamical behavior correlations with no classical counterpart, like entanglement, nonlocal and quantum discord, in open systems is primary interest because possibility to exploit these for information tasks. Here we review some most recent results on dynamics bipartite embedded non-Markovian environments that, their memory effects, influence a relevant way system appear be more fundamental than Markovian ones practical purposes. Firstly, phenomenon entanglement revivals...

Revivals of quantum correlations in composite open systems are a useful dynamical feature against detrimental effects the environment. Their occurrence is attributed to flows information back and forth from environments. However, revivals also show up models where environment classical, thus unable store correlations, forbids system-environment back-action. This phenomenon opens basic issues about its interpretation involving role classical environments, memory effects, collective...

Here is analyzed the dynamics of two-qubit entanglement, when two qubits are initially in a mixed extended Werner-like state and each them zero temperature non-Markovian environment. The dependence entanglement on purity degree initial states amount non-Markovianity also given. This extends previous work about effects for Bell-like [Bellomo et al., Phys. Rev. Lett. 99, 160502 (2007)]. effect nonzero Markovian environments finally studied.

The entanglement dynamics of two independent qubits each embedded in a structured environment under conditions inhibition spontaneous emission is analyzed, showing trapping. We demonstrate that trapping can be used efficiently to prevent sudden death. For the case realistic photonic band-gap materials, we show high values achieved. This result both fundamental and applicative interest since it provides physical situation where preserved manipulated, e.g. by Stark-shifting qubit transition...

Revivals of quantum correlations have often been explained in terms back-action on systems by their environment(s). Here we consider a system two independently evolving qubits, each locally interacting with classical random external field. The environments the qubits are also independent, and there is no qubits. Nevertheless, entanglement, discord, between may revive this model. We explain revivals classical-quantum state Although states cannot store entanglement own, they can play role...

Quantum technology relies on the utilization of resources, like quantum coherence and entanglement, which allow information computation processing. This achievement is however jeopardized by detrimental effects environment surrounding any system, so that finding strategies to protect resources essential. Non-Markovian structured environments are useful tools this aim. Here we show how a simple environmental architecture made two coupled lossy cavities enables switch between Markovian...

We show that the phenomenon of frozen discord, exhibited by specific classes two-qubit states under local nondissipative decoherent evolutions, is a common feature all known bona fide measures general quantum correlations. All those measures, despite inducing typically inequivalent orderings on set nonclassically correlated states, return constant value in considered settings. Every communication protocol which relies correlations as resource will run with performance completely unaffected...

Typical elements of quantum networks are made by identical systems, which the basic particles constituting a resource for information processing. Whether indistinguishability due to particle identity is an exploitable remains open issue. Here we study independently prepared showing that, when they spatially overlap, operational entanglement exists that can be manifest means separated localized measurements. We prove this physical in it directly exploited activate protocols, such as...

Quantum entanglement of identical particles is essential in quantum information theory. Yet, its correct determination remains an open issue hindering the general understanding and exploitation many-particle systems. Operator-based methods have been developed that attempt to overcome issue. We introduce a state-based method which, as second quantization, does not label presents conceptual technical advances compared previous ones. It establishes quantitative role played by arbitrary wave...

In this paper, we study how to preserve entanglement and nonlocality under dephasing produced by classical noise with large low-frequency components, such as $1/f$ noise, using dynamical decoupling techniques. We first show that quantifiers of satisfy a closed relation valid for two independent qubits locally coupled generic environment pure starting from general class initial states. This result allows us assess the efficiency pulse-based protecting nonlocal quantum correlations between...

We define and analyze measures of correlations for bipartite states based on trace distance. For Bell diagonal two qubits, in addition to the known expression quantum using this metric, we provide analytic expressions classical total correlations. The ensuing hierarchy distance is compared ones relative entropy Hilbert-Schmidt norm. Although some common features can be found, measure shown differentiate from others that closest uncorrelated state a given not by product marginals, further,...

Abstract In many applications entanglement must be distributed through noisy communication channels that unavoidably degrade it. Entanglement cannot generated by local operations and classical (LOCC), implying once it has been is not possible to recreate LOCC. Recovery of purely control however forbidden in the presence non-Markovian dynamics here we demonstrate two all-optical experiments such restoration can even achieved on-demand. First, implement an open-loop scheme based on a...

The ability to live in coherent superpositions is a signature trait of quantum systems and constitutes an irreplaceable resource for quantum-enhanced technologies. However, decoherence effects usually destroy superpositions. It was recently predicted that, composite system exposed dephasing noise, coherence transversal reference basis can stay protected indefinite time. This occur class states independently the measure used quantify coherence, it requires no control on during dynamics. Here,...

Quantum correlations in a composite system can be measured by resorting to geometric approach, according which the distance from state of suitable set classically correlated states is considered. Here we show that all functions, respect natural assumptions invariance under transposition, convexity, and contractivity quantum channels, give rise quantifiers exhibit peculiar freezing phenomenon, i.e., remain constant during evolution paradigmatic class two qubits each independently interacting...

Entanglement plays a crucial role in the development of quantum-enabled devices. One significant objective is deterministic creation and distribution entangled states, achieved, for example, through mechanical oscillator interacting with confined electromagnetic fields. In this study, we explore cavity resonator containing two-sided perfect mirror. Although mirror separates modes into two independent fields, radiation pressure interaction gives rise to high-order effective interactions...

Controlling the non-Markovian dynamics of open quantum systems is essential in information technology since it plays a crucial role preserving memory. Albeit many realistic scenarios system can simultaneously interact with composite environments, this condition remains little understood, particularly regarding effect coupling between environmental parts. We analyze behavior qubit interacting at same time two coupled single-mode cavities which turn dissipate into memoryless or memory-keeping...

The distance between a quantum state and its closest not having certain property has been used to quantify the amount of correlations corresponding that property. This approach allows unified view various kinds present in system. In particular, using relative entropy as measure, total can be meaningfully separated classical part thanks an additive relation involving only distances states. Here, we investigate measure square norm, already define so-called geometric discord. We thus consider...

Understanding the non-Markovian mechanisms underlying revivals of quantum entanglement in presence classical environments is central theory information. Tentative interpretations have been given by either role environment as a control device or concept hidden entanglement. We address this issue from an information-theoretic point view. To aim, we consider paradigmatic tripartite system, already realized laboratory, made two independent qubits and random field locally interacting with one...

We extend the Hilbert-Schmidt (square norm) distance, previously used to define geometric quantum discord, also quantifiers of total and classical correlations. then compare dynamics entropic different kinds correlations in a non-Markovian open two-qubit system under local dephasing. find that qualitative differences occur only for discords. This is taken imply discords are not, general, equivalent describing show present disagreements state space. aspect indicates found discord not...

Wave-particle duality is the most fundamental description of nature a quantum object which behaves like classical particle or wave depending on measurement apparatus. On other hand, entanglement represents nonclassical correlations composite systems, being also key resource in information. Despite very recent observations wave-particle superposition and entanglement, whether these two traits mechanics can emerge simultaneously remains an open issue. Here we introduce experimentally realize...

Efficient entanglement preservation in open quantum systems is a crucial scope towards reliable exploitation of resources. We address this issue by studying how two-qubit dynamically behaves when two atom qubits move inside separated identical cavities. The moving independently interact with their respective cavity. As main general result, we find that under resonant qubit-cavity interaction the initial between remains closer to its value as time passes compared case stationary qubits. In...

Abstract Initialization of composite quantum systems into highly entangled states is usually a must to enable their use for technologies. However, unavoidable noise in the preparation stage makes system state mixed, hindering this goal. Here, we address problem context identical particle within operational framework spatially localized operations and classical communication (sLOCC). We define entanglement formation an arbitrary two qubits. then introduce entropic measure spatial...

We study the entanglement dynamics for two independent superconducting qubits each affected by a bistable impurity generating random telegraph noise (RTN) at pure dephasing. The relevant parameter is ratio $g$ between qubit-RTN coupling strength and RTN switching rate, that captures physics of crossover Markovian non-Markovian features dynamics. For identical subsystems, threshold value $g_\mathrm{th}$ separates exponential decay onset revivals; different qualitative behaviors also show up...