  Confinement describes the phenomenon when the attraction between two
particles grows with their distance, most prominently found in quantum
chromodynamics (QCD) between quarks. In condensed matter physics, confinement
can appear in quantum spin chains, for example, in the one dimensional
transverse field Ising model (TFIM) with an additional longitudinal field,
famously observed in the quantum material cobalt niobate or in optical
lattices. Here, we establish that state-of-the-art quantum computers have
reached quantum simulation capabilities to explore confinement physics in spin
chains. We report quantitative confinement signatures of the TFIM on an IBM
quantum computer observed via two distinct velocities for information
propagation from domain walls and their mesonic bound states. We also find the
confinement induced slow down of entanglement spreading by implementing
randomized measurement protocols for the second order Renyi entanglement
entropy. Our results are a crucial step for probing non-perturbative
interacting quantum phenomena on digital quantum computers beyond the
capabilities of classical hardware.
