1998/07/08 by G. Lang, G Lang, E. Paladino +3
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Quantum and electron transport phenomena #Quantum optics and atomic interactions #cond-mat.stat-mech
paper · pdf · doi:10.1209/epl/i1998-00328-9
published as Europhys. Lett. 43, 117 (1998) · 5 pages, 5 figures, to be published in Europhys. Lett
arxiv created 1998/07/08 · openalex publication_date 1998/07/15 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
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 damping strength K = ½, 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 −2 K , whereas the position correlations show universal decay ∝ 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.