Harvesting entanglement from the Lorentz-violating quantum field vacuum in a dipolar Bose-Einstein condensate

We theoretically propose an experimentally viable scheme to explore the transfer of nonclassical correlations from a dipolar Bose-Einstein condensate (BEC) to a pair of impurities immersed in it. Operating at ultra-low temperature, density fluctuations of the dipolar BEC emulate a vacuum field with Lorentz-violating dispersion, while the two impurities function as Unruh-DeWitt detectors for the BEC quasiparticles. We study the harvesting of entanglement from the quantum vacuum of this analogue Lorentz-violating quantum field by spatially separated Unruh-DeWitt detectors. Our analysis reveals key parameter dependencies that optimize the harvesting of entanglement. In particular, unlike the Lorentz-invariant case, smoother detector switchings does not enhance the entanglement harvesting efficiency from the Lorentz-violating quantum field vacuum. Moreover, the strength of the Lorentz-invariant violation can shift the optimal energy structure of the detectors for harvesting entanglement from the Lorentz-violating quantum field vacuum-a clear deviation from the Lorentz-invariant scenario. As a fundamental quantum mechanical setup, our quantum fluid platform provides an experimentally realizable testbed for examining the entanglement harvesting protocol from an effective Lorentz-violating quantum field vacuum using a pair of impurity probers, which may also has potential implications for exploring the Lorentz-invariant violation in quantum field theory.

💡 Research Summary

The paper proposes a concrete, experimentally feasible protocol for harvesting entanglement from the vacuum of a Lorentz‑violating (LV) quantum field using a dipolar Bose‑Einstein condensate (BEC) as an analogue medium and two impurity atoms as Unruh‑DeWitt (UDW) detectors. The authors first show that density fluctuations in a quasi‑two‑dimensional dipolar BEC obey a Bogoliubov‑de Gennes equation whose dispersion relation can be tuned to the form
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