Description |
I will introduce an approach to study quantum many-body dynamics, inspired by the Feynman-Vernon influence functional. Its central object is the influence matrix (IM), which describes the effect of an extended quantum many-body system on the evolution of its local subsystems. For infinite translationally invariant systems, the bulk IM fully characterizes the action of the system as a bath on itself, and thus fully encodes large-scale universal aspects of dynamics (e.g., thermalization, localization, transport laws,…)
For certain fine-tuned Floquet systems, remarkably simple exact solutions appear, which represent perfect dephasers (PD), i.e., many-body systems acting as perfectly Markovian baths on their parts. Such PDs include dual-unitary quantum circuits investigated in recent works. Systems detuned away from PD points are not perfectly Markovian, but rather act as a quantum bath with a short memory time. This opens the door to efficient representations of the IM via matrix-product-states (MPS), as the underlying “principle of efficiency” only relies on the weakness of temporal correlations and entanglement. ***************************************************** Please remember that a valid green pass is needed to access SISSA. ***************************************************** |