Abstract We investigate the equilibrium and nonequilibrium quantum information correlations encoded in a two-qubit system in curved spacetime near the horizon of a Kerr black hole. We study the impact of mass and the angular momentum and further the local curvature or accelerations on the behaviors of the quantum correlations between the two qubits. We show that the quantum information of the two qubits is encoded in the spacetime structure. Concretely, the quantum correlations in the two-qubit system vary non-monotonically with the mass of the black hole and are amplified by the angular momentum, while the curvature suppresses the quantum correlations in the system. We show that the nonequilibrium can also contribute to the quantum correlations. Remarkably, the nonequilibrium can lead to the increase of quantum correlations in the steady state under the curved spacetime shown in this black hole example.
Abstract We investigate the equilibrium and nonequilibrium quantum information correlations encoded in a two-qubit system in curved spacetime near the horizon of a Kerr black hole. We study the impact of mass and the angular momentum and further the local curvature or accelerations on the behaviors of the quantum correlations between the two qubits. We show that the quantum information of the two qubits is encoded in the spacetime structure. Concretely, the quantum correlations in the two-qubit system vary non-monotonically with the mass of the black hole and are amplified by the angular momentum, while the curvature suppresses the quantum correlations in the system. We show that the nonequilibrium can also contribute to the quantum correlations. Remarkably, the nonequilibrium can lead to the increase of quantum correlations in the steady state under the curved spacetime shown in this black hole example.
Abstract The investigation of nonclassical correlations in curved spacetimes offers key insights into the intersection of quantum information theory and gravitational physics. This paper studies two nonlocal correlation measures, non local advantage of quantum coherence (NAQC) and Bell nonlocality (BN) in a d -dimensional spherically symmetric Einstein–Gauss–Bonnet (EGB) black hole spacetime. We consider two observers (Alice and Rob) initially sharing a maximally entangled Bell state: Alice freely falls into the black hole (inertial Kruskal frame), while Rob accelerates outside the horizon (non-inertial Schwarzschild-like frame). The Unruh–Hawking effect modifies Rob’s field modes, requiring Bogoliubov transformations to relate the two frames. We derive the mixed bipartite density matrix for fermionic fields and analytical expressions for NAQC and BN, which depend on Hawking temperature (itself governed by α α , d , and rh r h ). Our results show both correlations degrade monotonically with increasing Hawking temperature, confirm the NAQC-BN hierarchical relationship persists in EGB spacetime, and highlight higher-curvature corrections’ impact on quantum resources.
The investigation of nonclassical correlations in curved spacetimes offers key insights into the intersection of quantum information theory and gravitational physics. This paper studies two nonlocal correlation measures, non local advantage of quantum coherence (NAQC) and Bell nonlocality (BN) in a d-dimensional spherically symmetric Einstein-Gauss-Bonnet (EGB) black hole spacetime. We consider two observers (Alice and Rob) initially sharing a maximally entangled Bell state: Alice freely falls into the black hole (inertial Kruskal frame), while Rob accelerates outside the horizon (non-inertial Schwarzschild-like frame). The Unruh-Hawking effect modifies Rob's field modes, requiring Bogoliubov transformations to relate the two frames. We derive the mixed bipartite density matrix for fermionic fields and analytical expressions for NAQC and BN, which depend on Hawking temperature (itself governed by α, d, and rh). Our results show both correlations degrade monotonically with increasing Hawking temperature, confirm the NAQC-BN hierarchical relationship persists in EGB spacetime, and highlighting the impact of high curvature corrections on quantum resources.
Abstract We investigate how the Hawking effect reshapes distinct quantum resources of Dirac fields in Schwarzschild spacetime beyond the single-mode approximation. By quantifying quantum entanglement and coherence using the negativity, the l 1 -norm of coherence and the relative entropy of coherence, we observe a significant asymmetry in their response to gravitational effects. While the Hawking effect monotonically degrades entanglement and drives it toward a finite residual value, quantum coherence is instead monotonically amplified with increasing Hawking temperature, revealing the black hole as an effective decohering environment for nonlocal correlations but a coherence-enhancing mechanism for local superposition. Notably, we further find that under the influence of the Hawking effect, the maximally entangled state does not necessarily correspond to the largest initial negativity. In fact, its value may even be smaller than that of certain non-maximally entangled states. Our results demonstrate that gravity acts in a highly nonuniform manner on different facets of quantumness and highlight the necessity of resource-adapted state engineering for relativistic quantum information processing near the event horizon of the black hole.
We investigate the quantum entanglement properties of the Dirac field near a charged Reissner--Nordström black hole, incorporating the effects of Hawking radiation within the framework of quantum field theory in curved spacetime. Using concurrence C and Bures distance B as measures of entanglement, we analyze how quantum correlations evolve with respect to the electric charge Q of the black hole, the frequency ω of fermionic modes, and the initial entanglement angle θ. Our results show that the electric charge Q enhances decoherence inside the event horizon while, counterintuitively, temporarily increasing accessible entanglement outside. The Hawking effect induces an apparent loss of entanglement for an external observer, due to correlation transfer to inaccessible regions. High-frequency modes ω exhibit greater resilience to gravitational effects, maintaining robust correlations near the horizon. These findings highlight the redistribution of entanglement in a multipartite system in curved spacetime, with significant implications for quantum information in relativistic and gravitational contexts.
We investigate the quantum entanglement properties of the Dirac field near a charged Reissner–Nordström black hole, incorporating the effects of Hawking radiation within the framework of quantum field theory in curved spacetime. Using concurrence C and Bures distance B as measures of entanglement, we analyze how quantum correlations evolve with respect to the electric charge Q of the black hole, the frequency ω of fermionic modes, and the initial entanglement angle θ . Our results show that the electric charge Q enhances decoherence inside the event horizon while, counterintuitively, temporarily increasing accessible entanglement outside. The Hawking effect induces an apparent loss of entanglement for an external observer, due to correlation transfer to inaccessible regions. High-frequency modes ω exhibit greater resilience to gravitational effects, maintaining robust correlations near the horizon. These findings highlight the redistribution of entanglement in a multipartite system in curved spacetime, with significant implications for quantum information in relativistic and gravitational contexts.
Abstract We investigate the behavior of quantum correlations and quantum uncertainty in tripartite systems subjected to Hawking radiation in the background of a Schwarzschild black hole. By considering different bipartitions of accessible and inaccessible field modes separated by the event horizon, we analyze three complementary quantum information measures: the symmetry resolved entanglement entropy (SREE), the quantum speed limit (QSL), and the Wigner Yanase Skew information (SI). Our analysis shows that the QSL decreases monotonically with increasing Hawking temperature, indicating that Hawking radiation enhances the distinguishability of the reduced quantum states along the Hawking radiation trajectory. In contrast, the skew information decreases only for partitions composed solely of accessible modes, reflecting a reduction in local quantum uncertainty caused by thermal mixing. The SREE, however, decreases only when the subsystem includes the inaccessible inside horizon mode of Alice, revealing a suppression of symmetry sector mixing due to the redistribution of entanglement across the horizon. These results demonstrate that Hawking radiation does not simply degrade quantum correlations but instead redistributes them between accessible and inaccessible sectors of the field. The combined analysis of SREE, SI, and QSL therefore provides a unified perspective on how relativistic effects reshape quantum information in curved spacetime.