Physics

Qubit

Rare events

Mathematics

Non-equilibrium thermodynamics

Dynamical systems theory

Statistical physics

Statistics

Crossover

Open system (computing)

Artificial intelligence

Open quantum system

Markov process

Programming language

Software

Quantum system

Dynamical system (definition)

Computer science

Quantum mechanics

Quantum

Physical review. A/Physical review, A

Large dynamical fluctuations - atypical realizations of the dynamics sustained over long periods of time - can play a fundamental role in determining the properties of collective behavior of both classical and quantum non-equilibrium systems. Rare dynamical fluctuations, however, occur with a probability that often decays exponentially in their time extent, thus making them difficult to be directly observed and exploited in experiments. Here, using methods from dynamical large deviations, we explain how rare dynamics of a given (Markovian) open quantum system can always be obtained from the typical realizations of an alternative (also Markovian) system. The correspondence between these two sets of realizations can be used to engineer and control open quantum systems with a desired statistics "on demand". We illustrate these ideas by studying the photon-emission behaviour of a three-qubit system which displays a sharp dynamical crossover between active and inactive dynamical phases.

Making rare events typical in Markovian open quantum systems