Energy of the symmetrization entanglement

Abstract

When a measurement is carried out on one of the entangled parties, the second party can extract work owing to the reduction in its entropy. Here we inquire the amount of work/energy corresponding to the symmetrization entanglement of identical particles (bosons) in a condensate. One measures the quantum state of a particular boson which can be performed only under some certain conditions. We learn that the extracted work comes out to be the \textit{complete} thermodynamical energy present in the condensate. %We learn that the work extracted by the remaining part of the condensate is equal to the excitation energy of the measured boson times the thermodynamical probability of being in the excited state, i.e., $\hbar \omega_{eg} \times \exp(-\hbar \omega_{eg}/k_BT)$. We study the phenomenon in an interacting Bose-Einstein condensate. Then, we discuss that the results may also have fundamental implications on the pair creation in QED vacuum.