  Quantum computers offer an intriguing path for a paradigmatic change of
computing in the natural sciences and beyond, with the potential for achieving
a so-called quantum advantage, namely a significant (in some cases exponential)
speed-up of numerical simulations. The rapid development of hardware devices
with various realizations of qubits enables the execution of small scale but
representative applications on quantum computers. In particular, the
high-energy physics community plays a pivotal role in accessing the power of
quantum computing, since the field is a driving source for challenging
computational problems. This concerns, on the theoretical side, the exploration
of models which are very hard or even impossible to address with classical
techniques and, on the experimental side, the enormous data challenge of newly
emerging experiments, such as the upgrade of the Large Hadron Collider. In this
roadmap paper, led by CERN, DESY and IBM, we provide the status of high-energy
physics quantum computations and give examples for theoretical and experimental
target benchmark applications, which can be addressed in the near future.
Having the IBM 100 x 100 challenge in mind, where possible, we also provide
resource estimates for the examples given using error mitigated quantum
computing.
