Dynamics and quantum entanglement of two-level atoms in de Sitter spacetime

Abstract

In the framework of open quantum systems, we study the internal dynamics of both freely falling and static two-level atoms interacting with quantized conformally coupled massless scalar field in de Sitter spacetime. We find that the atomic transition rates depend on both the nature of de Sitter spacetime and the motion of atoms, interestingly the steady states for both cases are always driven to being purely thermal, regardless of the atomic initial states. This thermalization phenomenon is structurally similar to what happens to an elementary quantum system immersed in a thermal field, and thus reveals the thermal nature of de Sitter spacetime. Besides, we find that the thermal baths will drive the entanglement shared by the freely falling atom (the static atom) and its auxiliary partner, a same two-level atom which is isolated from external fields, to being sudden death, and the proper time for the entanglement to be extinguished is computed. We also analyze that such thermalization and disentanglement phenomena, in principle, could be understood from the perspective of table-top simulation experiment.

Detecting the Curvature of de Sitter Universe with Two Entangled Atoms

“…Therefore, the parameters of the de Sitter spacetime can in principle be probed using a pair of atoms interacting via the resonance Casimir-Polder interaction. It is interesting that the response of the single detector 25 26 28 in terms of the spontaneous emission rate, energy-level shift, and geometric phase 29 30 31 32 in de Sitter spacetime, shows that the detector seems as if it were immersed in a thermal bath with the temperature T = 1/2 πκ . However, the resonance interatomic interactions here manifest non-thermally, carrying no signatures of thermal fluctuations.…”

“…Let us note that the temperature T = 1/2 πκ actually can be written as . Here is the Gibbons-Hawking temperature, and T a = a /2 π is the Unruh temperature with being the proper acceleration of static atom 25 26 28 29 30 31 32 . Let us note that both T f and T a are associated with the curvature of de Sitter spacetime, i.e., R = 12/ α 2 26 .…”

“…More importantly, it is also a good model of our universe in the far past and the far future, as suggested by our current observations and the theory of inflation. It is known that a single particle interacting with a conformally coupled massless scalar field in the de Sitter invariant vacuum state behaves exactly the same way as the one coupled to thermal bath in Minkowski spacetime 25 26 27 28 29 30 31 32 . It is therefore difficult or impossible to distinguish the de Sitter spacetime from the Minkowski spacetime containing a thermal bath, with the use of a single locally coupled quantum system.…”

Relativistic motion enhanced quantum estimation of $$\kappa $$ κ -deformation of spacetime

“…Let us note that this model has been fruitfully applied in the relativistic scenario recently [43][44][45]58,[69][70][71][72][73]. The total Hamiltonian of the detector-field system can be described as…”

Entropic uncertainty in the background of expanding de Sitter space-time

“…The entanglement dynamics of atoms coupling with a fluctuating scalar field in de Sitter space-time was investigated in Ref. [23,24]. Further some authors discussed the behaviors of quantum correlation for atoms immersing in a fluctuating scalar field in de Sitter space-time [25,26].…”