Fast tests for probing the causal structure of quantum processes

The identification of causal relations is a cornerstone of the scientific method. Traditional approaches to this task are based on classical statistics. However, such classical approaches do not apply in the quantum domain, where a broader spectrum of causal relations becomes accessible. New approaches to quantum causal inference have been developed in recent years, and promising new features have been discovered. In this paper, we review and partly expand the framework and results of Ref. [1], which demonstrated quantum speedups in the identification of various types of causal relations induced by reversible processes.