Interaction-Induced Quantum Dephasing in Mesoscopic Rings
  Combining nonperturbative techniques with Monte Carlo simulations we demonstrate that quantum coherence effects for a particle on a ring are suppressed beyond a finite length $L_{\phi}$ even at zero temperature if the particle is coupled to a diffusive electron gas by means of long range Coulomb interaction. This length is consistent with $L_{\phi}$ derived from weak-localization-type of analysis. 
Dmitri S. Golubev, Carlos P. Herrero, and Andrei D. Zaikin