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Decay of correlations in the dissipative two-state system

G. Lang·E. Paladino·U. Weiss
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Abstract

We study the equilibrium correlation function of the polaron-dressed tunnelling operator in the dissipative two-state system and compare the asymptoptic dynamics with that of the position correlations. For an Ohmic spectral density with the damping strength $K=1/2$, the correlation functions are obtained in analytic form for all times at any $T$ and any bias. For $K<1$, the asymptotic dynamics is found by using a diagrammatic approach within a Coulomb gas representation. At T=0, the tunnelling or coherence correlations drop as $t^{-2K}$, whereas the position correlations show universal decay $\propto t^{-2}$. The former decay law is a signature of unscreened attractive charge-charge interactions, while the latter is due to unscreened dipole-dipole interactions.

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G. Lang, E. Paladino, U. Weiss. 1998-07-08. Decay of correlations in the dissipative two-state system. https://doi.org/10.1209/epl%2Fi1998-00328-9

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