Entanglement of two distinguishable atoms in a rectangular waveguide: Linear approximation with single excitation

We investigate the entanglement dynamics of two distinguishable two-level systems (TLSs) characterized by energy difference δ located inside a rectangular hollow metallic waveguide of transverse dimensions a and b. The effects of energy difference δ and the inter-TLS distance on the time evolution of the concurrence of the TLSs are examined in the single excitation subspace when the energy separation of the TLS is far away from the cutoff frequencies of the transverse mode.