Temperature dependence of quantum correlations in 1D macromolecular chains

We investigate the problem of generating quantum correlations between different sites of a macromolecular chain by vibronic excitation depending on the temperature. The influence of temperature on the model dynamics is taken into account by employing the partial-dressing method based on the modified Lang–Firsov unitary transformation under the assumption that the chain collective oscillations are in the thermal equilibrium state. To describe quantum correlations between the chain sites in the case of the initial single-vibronic excitation, we use two-time correlation functions of the second order and the logarithmic negativity as the degree of entanglement. We find that at certain temperatures for various model parameters time-stable entanglement can occur in the chain.