Quantum jump unravelings for non-Markovian open system dynamics: a review

TL;DR

This review discusses quantum jump unraveling techniques for non-Markovian open quantum systems, addressing their theoretical foundations, numerical efficiency, and measurement interpretations, filling a gap in comprehensive understanding.

Contribution

It provides a comprehensive overview of quantum jump methods for non-Markovian dynamics, comparing their features and discussing recent developments.

Findings

Reviewed various jump techniques for non-Markovian systems.

Analyzed numerical efficiency and divisibility requirements.

Discussed measurement interpretations of the methods.

Abstract

Stochastic unravelings provide a useful way to represent open quantum system dynamics in terms of pure state realizations, and have been widely studied both from a fundamental and from a computational point of view. They were initially formulated for Markovian dynamics described by the Gorini-Kossakowski-Sudarshan-Lindblad master equation. However, due to recent technological and experimental development, most physical relevant dynamics present temporal correlations beyond the Markov approximation. Such correlations cause decay rates to turn temporarily negative, thus requiring the generalization of stochastic unravelings from Markovian to non-Markovian scenarios. Indeed, many unraveling techniques have been introduced in this regime, and a comprehensive review of the different jump methods is currently missing. In this work, we provide an overview of widely used quantum jump unraveling techniques for non-Markovian systems and also discuss them in terms of their numerical efficiency, divisibility requirements, Hilbert space extension, and measurement interpretation.