Quantifying non-Markovianity in the linear response regime
Held by Dr. Philipp Strasberg (Université du Luxembourg,
14.12.2017, 14:00 Uhr
The question how to define and how to quantify non-Markovianity in the quantum regime has recently become a very active research topic. In the first part of this talk I will briefly review existing approaches. Motivated by the fact that previously proposed measures of non-Markovianity are extremly difficult to evaluate, I will then propose a much simplier way to quantify non-Markovianity with the drawback that it is limited to time-homogeneous processes in the linear response regime. For the often studied Caldeira-Leggett model, where linear response is actually generally valid, the new measure can be expressed analytically in terms of an integral over known functions. We will see that even a classical particle coupled to an Ohmic bath can behave non-Markovian, a phenomenon related to the initial state preparation procedure. Finally, we also study our measure for a peaked spectral density.