Nonlocal quantum correlations under amplitude damping decoherence

Abstract

Different nonlocal quantum correlations of entanglement, steering and Bell nonlocality are defined with the help of local hidden state (LHS) and local hidden variable (LHV) models. Considering their unique roles in quantum information processing, it is of importance to understand the individual nonlocal quantum correlation as well as their relationship. Here, we investigate the effects of amplitude damping decoherence on different nonlocal quantum correlations. In particular, we have theoretically and experimentally shown that the entanglement sudden death phenomenon is distinct from those of steering and Bell nonlocality. In our scenario, we found that all the initial states present sudden death of steering and Bell nonlocality, while only some of the states show entanglement sudden death. These results suggest that the environmental effect can be different for different nonlocal quantum correlations, and thus, it provides distinct operational interpretations of different quantum correlations. arXiv:1910.06483v1 [quant-ph]

Sharing quantum steering among multiple Alices and Bobs via a two-qubit Werner state

“…Obviously, the unsharp measurement strategy used here is optimal. For Werner state, the classical bound C N = {1/ √ 2, 1/ √ 3, 1/ √ 3, 0.5393, 0.5236, 0.503, 0.5} when N = {2, 3, 4, 6, 10, 16, ∞}, respectively [42,44]. Since the classical bound of N = 16 is very close to that of infinite measurement settings, we implement N = {2, 3, 4, 6, 10, 16} to investigate the behavior of quantum steering in this work.…”

“…Note that if the disturbance caused by the former observer's measurement is regarded as noise, our steering sharing protocol can also be applied to investigate the dynamic of steering in the presence of decoherence [44], such as steering sudden death and revival…”

Decoherence-Induced Sudden Death of Entanglement and Bell Nonlocality

“…It has been widely studied that the effect of decoherence on a bipartite entangled state results in ESD and BNSD both in theory and experiment [22][23][24][25][26][27]. However, these studies have been focused on the two types of decoherence, amplitude damping and phase damping.…”

Quantum steering and quantum discord under noisy channels and entanglement swapping

“…Quantum features such as coherence and correlations play a fundamental role in quantum foundations as well as in practical matters like the development of quantum technologies [1][2][3][4]. In particular, quantum optics stands out as a key field of research, due to photonic devices allowing for the experimental implementation of quantum informationtheoretic protocols, where quantum correlations can be detected, tested, and exploited [5][6][7].…”

“…In particular, quantum optics stands out as a key field of research, due to photonic devices allowing for the experimental implementation of quantum informationtheoretic protocols, where quantum correlations can be detected, tested, and exploited [5][6][7]. There exists nowadays a whole zoo of different quantum properties which are deemed as potential resources 1 , and which can be broadly classified as: i) entanglement-based correlations, meaning correlations which necessarily require the presence of entanglement for them to exist and ii) above-entanglement correlations, which aim at capturing non-classicality beyond that of entanglement. Entanglement-based correlations include properties like: a) Bell-nonlocality, which is arguably the most restrictive amongst these properties [8], b) EPR-steering, which is conceived as the possibility of remotely generating ensembles of quantum states not obeying local hidden state (LHS) models [9], and which has become of great research interest due to its usefulness for device-independent protocols [7,10], and c) usefulness for teleportation, which provides information on how useful a state is for the standard teleportation scheme [11].…”