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We consider quantum entanglement of three accelerating qubits, each of which is locally coupled with a real scalar field, without causal influence among the qubits or among the fields. The initial states are assumed to be the GHZ and the W states, which are the two representative three-partite entangled states. For each initial state, we study how various kinds of entanglement depend on the accelerations of the three qubits. All kinds of entanglement eventually suddenly die if at least two of three qubits have large enough accelerations. This result implies eventual sudden death of all kinds of entanglement among three particles coupled with scalar fields when they are sufficiently close to the horizon of a black hole.

[5-(5,6-Dihydro-4H-pyridin-3-ylidenemethyl)furan-2-yl]methanol, also called F3-A, has been isolated from hexose-lysine Maillard reaction (MR) models. Here we report on optimized conditions for the recovery of F3-A and concentrations found in bread. Recovery of F3-A was best achieved when samples were extracted with dichloromethane (DCM) at a solvent to sample ratio of 2:1 (v/v) after adjustment of the pH to 12. The amount of F3-A in whole wheat bread was significantly (P < 0.05) higher than that in white bread; bread crust contained a significantly (P < 0.05) higher amount of F3-A (0.9-7.8 μg/100 g) than the bread crumb (not detectable-3.5 μg/100 g); and toasting increased F3-A concentration with a range of not detectable to 6.0 μg/100 g in the control bread and 4.0 and 17.7 μg/100 g in the dark-toasted white sandwich bread and 100% whole wheat sandwich bread, respectively. The in vitro permeability of F3-A was measured using Caco-2 cell monolayer. The apparent permeability coefficient (P) of F3-A is (6.01 ± 0.35) × 10 cm/s, which is similar to that of propranolol, a highly passive transcellular absorbed drug. In conclusion, the concentration of F3-A recovered in bread varies with the type of bread and degree of toasting, and F3-A is bioavailable.

The theory of phase control of coherence, entanglement and quantum steering is developed for an optomechanical system composed of a single mode cavity containing a partially transmitting dielectric membrane and driven by short laser pulses. The membrane divides the cavity into two mutually coupled optomechanical cavities resulting in an effective three-mode closed loop system, two field modes of the two cavities and a mechanical mode representing the oscillating membrane. The closed loop in the coupling creates interfering channels which depend on the relative phase of the coupling strengths of the field modes to the mechanical mode. Populations and correlations of the output modes are calculated analytically and show several interesting phase dependent effects such as reversible population transfer from one field mode to the other, creation of collective modes, and induced coherence without induced emission. We find that these effects result from perfect mutual coherence between the field modes which is preserved even if one of the modes is not populated. The inseparability criterion for the output modes is also investigated and we find that entanglement may occur only between the field modes and the mechanical mode. We show that depending on the phase, the field modes can act on the mechanical mode collectively or individually resulting, respectively, in tripartite or bipartite entanglement. In addition, we examine the phase sensitivity of quantum steering of the mechanical mode by the field modes. Deterministic phase transfer of the steering from bipartite to collective is predicted and optimum steering corresponding to perfect EPR state can be achieved. These different types of quantum steering can be distinguished experimentally by measuring the coincidence rate between two detectors adjusted to collect photons of the output cavity modes. In particular, we find that the minima of the interference pattern of the coincidence rate signal the bipartite steering, while the maxima signal the collective steering. distant system, as considered in the original Einstein-Podolsky-Rosen (EPR) paradox [10]. The EPR steering allows two parties to verify the shared entanglement even if one measurement device is untrusted, which makes it an essential resource for one-sided device independent quantum cryptography [11][12][13][14][15][16], one-way quantum computing [17,18], secure quantum teleportation [19,20], and subchannel discrimination [21].Recent studies have revealed that coherence is closely related to entanglement and quantum steering. It was pointed out by Suzuki et al [22] that entanglement can be detected from interference fringes in atom-photon systems. It has also been shown that the coherence in a system and entanglement between that system and another initially incoherent one are quantitatively, or operationally, equivalent [23]. The power of quantum steering for the generation of coherence has also been demonstrated [24,25]. It has been shown that the presence of mutual coherence among two systems may have a ...

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We consider two entangled accelerating qubits coupled with real scalar fields, each described by the Unruh-Wald model. It is demonstrated that because of the Unruh effect of the fields, the bipartite entanglement between the two qubits suddenly dies when the acceleration of one or more qubits are large enough. We also consider three entangled accelerating qubits in GHZ state and in W state, with equal acceleration-frequency ratio, and found that in either state, the tripartite entanglement suddenly dies at a certain value of acceleration-frequency ratio. The equivalence between the Rindler metric and the Schwarzschild metric in the vicinity of the horizon of a black hole implies that for two entangled qubits outside a black hole, the entanglement suddenly dies when one or both of the qubits are close enough to the horizon, while the three entangled qubits in GHZ or W state, the tripartite entanglement suddenly dies when these qubits are close enough to the horizon.

Quantum entanglement is the characteristic quantum correlation. Here we use this concept to analyze the quantum entanglement generated by Schwinger production of particle-antiparticle pairs in an electric field, as well as the change of mode entanglement as a consequence of the electric field effect on an entangled pair of particles. The system is partitioned by using momentum modes.Various kinds of pairwise mode entanglement are calculated as functions of the electric field. Both constant and pulsed electric fields are considered. The use of entanglement exposes information beyond that in particle number distributions.