  Quantum simulation has the potential to be an indispensable technique for the
investigation of non-perturbative phenomena in strongly-interacting quantum
field theories (QFTs). In the modern quantum era, with Noisy Intermediate Scale
Quantum~(NISQ) simulators widely available and larger-scale quantum machines on
the horizon, it is natural to ask: what non-perturbative QFT problems can be
solved with the existing quantum hardware? We show that existing noisy quantum
machines can be used to analyze the energy spectrum of a large family of
strongly-interacting 1+1D QFTs. The latter exhibit a wide-range of
non-perturbative effects like `quark confinement' and `false vacuum decay'
which are typically associated with higher-dimensional QFTs of elementary
particles. We perform quench experiments on IBM's ibmq_mumbai quantum simulator
to compute the energy spectrum of 1+1D quantum Ising model with a longitudinal
field. The latter model is particularly interesting due to the formation of
mesonic bound states arising from a confining potential for the Ising
domain-walls, reminiscent of t'Hooft's model of two-dimensional quantum
chromodynamics. Our results demonstrate that digital quantum simulation in the
NISQ era has the potential to be a viable alternative to numerical techniques
such as density matrix renormalization group or the truncated conformal space
methods for analyzing QFTs.
