Equilibration of multitime quantum processes in finite time intervals
Abstract
A generic non-integrable (unitary) out-of-equilibrium quantum process, when interrogated across many times, is shown to yield the same statistics as an (non-unitary) equilibrated process. In particular, using the tools of quantum stochastic processes, we prove that under loose assumptions, quantum processes equilibrate within finite time intervals. Sufficient conditions for this to occur are that multitime observables are coarse grained in both space and time, and that the initial state overlaps with many different energy eigenstates. These results help bridge the gap between (unitary) quantum and (non-unitary) statistical physics, i.e., when all multitime properties and correlations are well approximated by stationary quantities, which includes non-Markovianity and temporal entanglement. We discuss implications of this result for the emergence of classical stochastic processes from multitime measurements of an underlying genuinely quantum system.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 14, 2023
- Source ID
- 10.21468/scipostphyscore.6.2.043
Entities
People
- Felix A. Pollock
- Kavan Modi
- Neil Dowling
- Pedro Figueroa-romero
- Philipp Strasberg
Organizations
- Agencia Estatal de Investigación
- Air Force Office of Scientific Research
- Australian Government
- Australian Research Council
- Autonomous University of Barcelona
- Generalitat of Catalonia
- La Caixa
- Ministry of Economy, Industry and Competitiveness
- Monash University