Satellite‐Based Quantum Steering under the Influence of Spacetime Curvature of the Earth

Abstract

Spacetime curvature of the Earth deforms wave packets of photons sent from the Earth to satellites, thus influencing the quantum state of light. We show that Gaussian steering of photon pairs, which are initially prepared in a two‐mode squeezed state, is affected by the curved spacetime background of the Earth. We demonstrate that quantum steerability of the state increases for a specific range of height h and then gradually approaches a finite value with further increasing height of the satellite's orbit. Comparing with the peak frequency parameter, the Gaussian steering changes more for different squeezing parameters, while the gravitational frequency effect leads to quantum steering asymmetry between the photon pairs. In addition, we find that the influence of spacetime curvature on the steering in the Kerr spacetime is very different from the non‐rotating case because special relativistic effects are involved.

Gravity enhanced quantum spatial target detection

“…In realistic situation, the preparation of quantum state and implement of quantum information tasks are inevitably influenced by relativistic effects because gravitational interaction is nonmaskable. Therefore, it is significant to study how gravitational effect of the Earth influences quantum systems in laboratories [10] or long-distance quantum information processing tasks [11][12][13][14][15][16][17][18]. The studies of quantum information in relativistic settings are believed to provide new insights into some key questions in quantum mechanics and relativity, such as nonlocality, causality, and the information paradox of black holes.…”

“…To this end, the framework for the quantum information description of the Earth's gravity on quantum state of photons was introduced in [11]. Such method has been employed to study quantum communication [11,12], quantum metrology [13][14][15], quantum correlations [16,17], and quantum clock synchronization [18] under the influence of spacetime curvature of the Earth. In the scenario of spatial target detection, the transmission of signal beam inevitably involves long distances in curved spacetime, therefore the spacetime effect of the Earth should be seriously considered [19,20].…”

Generation of genuine tripartite entanglement for continuous variables in de Sitter space

“…(12), one can compute the bipartite contangles in different 1 → 2 partitions of the state given in Eq. (17), which are found to be…”

Quantum steering for continuous variable in de Sitter space

“…In practice, different from the Bell tests, the demonstration of quantum steerability which is free of detection and locality loopholes is in reach [7], which make quantum steerability a ponderable concept in quantum information theory. For the foregoing reasons, quantum steerability has recently attracted increasing interest both from theoretical [8][9][10][11][12][13][14][15][16][17] and experimental [18][19][20][21][22] perspectives. Most recently, Tischler et.al reported an experimental demonstration of unidirectional steering, which is free either of the restrictions on the type of allowed measurements or of assumptions about the quantum state at hand [23].…”