  We present a novel benchmark application of a quantum algorithm to Feynman
loop integrals. The two on-shell states of a Feynman propagator are identified
with the two states of a qubit and a quantum algorithm is used to unfold the
causal singular configurations of multiloop Feynman diagrams. To identify such
configurations, we exploit Grover's algorithm for querying multiple solutions
over unstructured datasets, which presents a quadratic speed-up over classical
algorithms when the number of solutions is much smaller than the number of
possible configurations. A suitable modification is introduced to deal with
topologies in which the number of causal states to be identified is nearly half
of the total number of states. The output of the quantum algorithm in \emph{IBM
Quantum} and \emph{QUTE Testbed} simulators is used to bootstrap the causal
representation in the loop-tree duality of representative multiloop topologies.
The algorithm may also find application and interest in graph theory to solve
problems involving directed acyclic graphs.
