Eigenstate entanglement for weakly interacting bipartite chaotic Bose-Hubbard systems

An analytic prediction for the eigenstate entanglement of a bipartite system with fully quantum chaotic subsystems was recently given as a function of coupling strength [1,2]. The importance of the transition parameter in identifying universal scaling laws governing the entropy were emphasized and coupled kicked rotors provided an example. The question is whether these scaling laws apply to bipartite many-body systems, such as a pair of weakly coupled Bose-Hubbard rings with parameters chosen so as to exhibit quantum chaos. Preliminary results suggest that the breakdown of internal symmetries as the interaction between the subsystems is turned on play a role in governing the extent of entanglement, which eventually approaches the predictions of random matrix theory for sufficiently strong interactions between the subsystems.

[1] S. L. Srivastava, S. Tomsovic, A. Lakshminarayan, R. Ketzmerick, A. Bäcker, Phys. Rev. Lett. 116, 054101

[2] S. Tomsovic, A. Lakshminarayan, S. L. Srivastava, A. Bäcker, Phys. Rev. E 98, 032209