In the past decade, the toolkit of quantum information has been expanded to include
processes in which the basic operations do not have definite causal relations. Originally …

Quantum theory is compatible with scenarios in which the order of operations is indefinite.
Experimental investigations of such scenarios, all of which have been based on a process …

We study the notion of causal orders for the cases of (classical and quantum) circuits and
spacetime events. We show that every circuit can be immersed into a classical spacetime …

The capacity of distant parties to send signals to one another is a fundamental requirement
in many information-processing tasks. Such ability is determined by the causal structure …

The field of indefinite causal order (ICO) has seen a recent surge in interest. Much of this
research has focused on the quantum switch, wherein multiple parties act in a superposition …

For minimum-error channel discrimination tasks that involve only unitary channels, we show
that sequential strategies may outperform the parallel ones. Additionally, we show that …

In the classical world, physical events always happen in a fixed causal order. However, it
was recently revealed that quantum mechanics allows events to occur with indefinite causal …

Quantum processes are transformations that act on quantum operations. Their study led to
the discovery of the phenomenon of indefinite causal order: some quantum processes, such …

While the standard formulation of quantum theory assumes a fixed background causal
structure, one can relax this assumption within the so-called process matrix framework …

The study of indefinite causal order has seen rapid development, both theoretically and
experimentally, in recent years. While classically the causal order of two timelike separated …