Measured Composite Collision Models: Quantum Trajectory Purities and Channel Divisibility

Research output: Contribution to journalResearch articleContributedpeer-review


We investigate a composite quantum collision model with measurements on the memory
part, which effectively probe the system. The framework allows us to adjust the measurement
strength, thereby tuning the dynamical map of the system. For a two-qubit setup with a symmetric
and informationally complete measurement on the memory, we study the divisibility of the resulting
dynamics in dependence of the measurement strength. The measurements give rise to quantum
trajectories of the system and we show that the average asymptotic purity depends on the specific
form of the measurement. With the help of numerical simulations, we demonstrate that the different
performance of the measurements is generic and holds for almost all interaction gates between the
system and the memory in the composite collision model. The discrete model is then extended to a
time-continuous limit


Original languageEnglish
Article number715
Pages (from-to)715
Number of pages1
Issue number5
Publication statusPublished - 17 May 2022

External IDs

dblp journals/entropy/BeyerLLS22
Mendeley 5becbe85-11f8-3200-afb0-164537912b16
PubMed 35626598
WOS 000802558200001
Scopus 85130990139
ORCID /0000-0002-7806-3525/work/142234206


DFG Classification of Subject Areas according to Review Boards


  • collision models, quantum measurements, non-Markovian quantum dynamics

Library keywords