Memory effects in quantum dynamical processes involving structured environments are presently difficult, if not impossible, to investigate using standard approaches. Progress can be made by transforming the environmental variables to a suitable chain representation which effectively performs a Markovian embedding of the dynamics. Here, we show that this effective-mode chain representation provides a unique way of unraveling the memory kernel κ(t) as a function of time. Truncated or Markov-closed chains with n effective modes exactly reproduce κ(t) to the 4nth order in time, up to an irrelevant constant of order κ(0)/n. These favorable convergence properties pave the way for efficient quantum simulations of fast (non-Markovian) processes by reduced dynamical models.
|Titolo:||Unraveling a Brownian particle’s memory with effective mode chains|
MARTINAZZO, ROCCO (Primo)
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
|Data di pubblicazione:||14-set-2011|
|Digital Object Identifier (DOI):||10.1103/PhysRevE.84.030102|
|Appare nelle tipologie:||01 - Articolo su periodico|