Restrictions on initial system-environment correlations based on the dynamics of an open quantum system

Eric Chitambar, Ali Abu-Nada, Russell Ceballos, Mark Byrd

Research output: Contribution to journalArticlepeer-review


The dynamics of an open quantum system is often modeled by introducing a bath initially in a product state with the system, letting the system and bath evolve unitarily together, and then tracing over the bath. However, often this model may not accurately reflect a particular experimental situation. Here, we provide some restrictions on one's ability to model an open quantum system using an initial product state when some information about the system-bath interaction is known. For instance, when certain symmetries exist in the system-bath interaction, we compute limitations on how much the system's purity can be increased if the bath is initially uncorrelated white noise. Furthermore, when the system and bath are qubits, we find that effectively only swap and product unitaries always generate system dynamics capable of being modeled using an initial product state. Finally, we show how any initial correlations between the system and environment are detectable, in principle, by observing the system transformation alone during certain joint evolutions. Our results have application in experimental quantum control and quantum computing where the system and environment are often assumed to be initially uncorrelated.

Original languageEnglish (US)
Article number052110
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Issue number5
StatePublished - Nov 16 2015
Externally publishedYes

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics


Dive into the research topics of 'Restrictions on initial system-environment correlations based on the dynamics of an open quantum system'. Together they form a unique fingerprint.

Cite this