Entanglement harvesting in the presence of a reflecting boundary

Abstract

We study, in the framework of entanglement harvesting protocols, the entanglement harvesting of a pair of uniformly accelerated detectors locally interacting with vacuum massless scalar fields subjected to a perfectly reflecting plane boundary. We find that the presence of the boundary generally degrades the amount of the harvested entanglement when two detectors are very close to the boundary for all three acceleration scenarios of the detectors with respect to the boundary, i.e., parallel, anti-parallel and mutually perpendicular acceleration. However, when the distance between detectors and the boundary becomes comparable to the interaction duration parameter, the amount of harvested entanglement may approach a peak, which even goes beyond that without a boundary. Remarkably, the parameter space of the detectors' separation and the magnitude of acceleration that allows entanglement harvesting to occur is enlarged due to the presence of the boundary. In this sense, the boundary plays a double-edged role on entanglement harvesting, degrading in general the amount of entanglement while enlarging the harvesting-achievable parameter space. A comparison of three different acceleration scenarios shows that the phenomena of entanglement harvesting crucially depends on the magnitude of acceleration, the separation between two detectors and the detectors' distance from the boundary.

Entanglement harvesting in cosmic string spacetime

“…In addition, the dependence of concurrence on the detector-to-boundary distance in a flat spacetime with a reflecting plane boundary is also depicted in these plots for comparison. To facilitate this comparison, we refer to the results for the case with a reflecting boundary in JHEP06(2024)161 a flat spacetime, as detailed in references [23,28]. The transition probability of the detector, according to these studies, satisfies [see eq.…”

“…The phenomenon of entanglement harvesting has since been explored across various settings . Entanglement harvesting has been shown to be highly sensitive to several aspects of spacetime, including its topology [12,23,28] and curvature [11,[13][14][15][16], and those of the detectors, such as their superpositions of temporal order [21], intrinsic motion [18,20,23,24] and energy gaps [26][27][28]. It has been argued that this sensitivity to topology can serve as a tool to differentiate between locally flat spacetimes that are distinct only in their topological structures [12].…”

“…Recent studies have uncovered that the presence of a reflecting boundary in a flat spacetime, effectively rendering the spacetime topologically nontrivial, plays a notable role in the dynamics of entanglement harvesting. Specifically, it has been found to inhibit entanglement harvesting close to the boundary while facilitating it further away [23,28].…”

Entanglement Harvesting of Inertially Moving Unruh-DeWitt Detectors in Minkowski Spacetime

“…The property of UDWs in the static limit have been well-explored in the past: it is known how entanglement harvesting depends on detector parameters such as their energy gaps and separation [26], the state of the quantum field [27] and the presence of boundaries [28][29][30]. For simplicity the detectors are generally taken to be identical.…”

Unruh-DeWitt detector's response to a non-relativistic particle

“…As a simple and useful tool, the UDW detector has also received considerable attention in many other areas, including the study of black hole thermodynamics [3,4], Lorentz-violating dispersion relations [5][6][7], finite spacial extensions of the detector and the corresponding regularization schemes [8][9][10][11][12], and the coupling to a fermionic field [13][14][15][16] (for more examples, see recent reviews [17][18][19] and references therein). More recently, UDW detectors have been used extensively in the so-called entanglement harvesting protocol [20], where a pair of UDW detectors coupled to a quantum field can be used to extract the vacuum entanglement of the field, and therefore to probe the nontrivial field properties in a wide range of scenarios [21][22][23][24][25][26][27][28][29][30][31][32][33][34].…”