We investigate multipartite total amount of correlations by analyzing the mutual information of N-partite states for both free bosonic and fermionic fields in the background of a Garfinkle-Horowitz-Strominger (GHS) dilaton black hole. Focusing on multipartite GHZ and W states, we examine how the Hawking effect influences the N-partite mutual information when one observer hovers near the event horizon while the remaining observers stay in the asymptotically flat region. By tracing over the inaccessible modes inside the event horizon, we derive analytical expressions for the N-partite mutual information in dilaton spacetime for both bosonic and fermionic fields. Our results show that fermionic mutual information is larger than its bosonic counterpart under the influence of the dilaton black hole, whereas the fermionic relative entropy of coherence (REC) is smaller than the bosonic REC. Moreover, the mutual information of GHZ states is consistently larger than that of W states, while the REC of GHZ states is smaller than that of W states in curved spacetime. These findings reveal distinct behaviors of multipartite mutual information and quantum coherence for different particle statistics and multipartite state structures under gravitational effects, providing further insight into many-body total correlations in curved spacetime.
It has traditionally been believed that fermionic entanglement generally outperforms bosonic entanglement in relativistic frameworks, and that bosonic entanglement experiences sudden death in extreme gravitational environments. In this study, we analyze the genuine N-partite entanglement, measured by negativity, of bosonic and fermionic GHZ states, focusing on scenarios where a subset of
m (
m<N) constituents interacts with Hawking radiation generated by a Garfinkle-Horowitz-Strominger (GHS) dilaton black hole. Surprisingly, we find that quantum entanglement between the non-gravitational and gravitational modes for the bosonic field is stronger than that in the same modes for the fermionic field within dilaton spacetime. This study challenges the traditional belief that ``fermionic entanglement always outperforms bosonic entanglement" in the relativistic framework. However, quantum entanglement between the gravitational modes and the combined gravitational and non-gravitational modes is weaker for the bosonic field than for the fermionic field in the presence of a dilaton black hole. Finally, the connection between the global N-partite entanglement in the bosonic field and that in the fermionic field is influenced by the gravitational field's intensity. Our study reveals the intrinsic relationship between quantum entanglement of bosonic and fermionic fields in curved spacetime from a new perspective, and provides theoretical guidance for selecting appropriate field-based quantum resources for relativistic quantum information tasks under extreme gravitational conditions.
A bstract We study the N-partite coherences of GHZ and W states for free bosonic and fermionic fields when any n observers hover near the event horizon of a Garfinkle-Horowitz-Strominger (GHS) dilaton black hole. We derive the more general analytical expressions for N-partite coherence, encompassing both physically accessible and inaccessible coherences in the context of the dilaton black hole. It has been found that the coherence of the bosonic field is greater than that of the fermionic field, while the entanglement of the fermionic field is greater than that of the bosonic field in dilaton spacetime. Additionally, the coherence of the W state is greater than that of the GHZ state, whereas the entanglement of the GHZ state is greater than that of the W state in curved spacetime. These results suggest that we should utilize suitable quantum resources and different types of particles for relativistic quantum information tasks.
We investigate the nonseparability of multipartite bosonic and fermionic
GHZ and
W states in a causal diamond spacetime using the Abe-Rajagopal (AR)
q-conditional entropy. The finite lifetime of the observer gives rise to a causal diamond horizon, which induces an Unruh-like thermal effect and leads to a nontrivial restructuring of nonseparability in
N-partite systems. Our main result is that the thermal effect can enhance a net nonseparability of fermionic
W states, in sharp contrast to the general expectation that relativistic thermalization leads to a monotonic degradation of bosonic nonseparability. In addition, we find that fermionic nonseparability is generally more robust than its bosonic counterpart under causal diamond restrictions. Among different entangled resources,
GHZ states exhibit stronger nonseparability and greater robustness than
W states under identical causal conditions. We further show that the nonseparability of
W states decreases with increasing particle number
N, whereas that of
GHZ states remains independent of
N in causal diamond spacetime. These results demonstrate that particle statistics, entanglement structure, and observer lifetime jointly determine the persistence of nonseparability in causally restricted spacetimes, providing insights for relativistic quantum information processing.
Abstract It is commonly assumed that a maximally multipartite entangled state carries greater quantum resources than a non-maximally multipartite entangled state in the relativistic framework. In this work, we analyze genuine N-partite entanglement of fermionic modes near the event horizon of the Garfinkle–Horowitz–Strominger (GHS) black hole, quantified by concurrence. Remarkably, our results reveal that in dilaton spacetime the genuine multipartite entanglement of a maximally entangled state is actually smaller than that of a non-maximally entangled state. From the perspective of quantum resources, this implies that a non-maximally entangled state may outperform a maximally entangled one in the GHS black hole background, in clear contrast to previous expectations. Furthermore, given the experimental challenges in preparing a maximally entangled state and the relative feasibility of preparing a non-maximally entangled state, our findings suggest that employing a suitably chosen non-maximally entangled state as the initial resource in curved spacetime provides a more practical and advantageous strategy for quantum information tasks.
Abstract The coherence of a quantum system can be considered as the available physical resource, and its quantification respects the choice of reference bases. In this paper, we propose the uncertainty relations for quantum coherence (URQC) of a bipartite system AB in mutually unbiased bases, where particle A is the measured particle and B is regarded as the quantum memory. It is confirmed that the Holevo quantity can improve the lower bound of coherence. By defining the tightness as the difference between coherence and its lower bound, we find that the tightness of the improved URQC is independent of the quantum memory. As an example of application, we investigate the URQC of Dirac particles in the background of a Garfinkle–Horowitz–Strominger dilaton black hole beyond the single-mode approximation. It shows that the lower bound of coherence decreases monotonically with the increase of dilaton parameter due to the Hawking effect. Moreover, since the subsystem A is not affected by the black hole, the tightness of the improved URQC is always keep constant. It worth mentioning that the change of coherence can be precisely predicted via the known tightness and the improved lower bound measured experimentally.