  Simulating computationally intractable many-body problems on a quantum
simulator holds great potential to deliver insights into physical, chemical,
and biological systems. While the implementation of Hamiltonian dynamics within
a quantum simulator has already been demonstrated in many experiments, the
problem of initialization of quantum simulators to a suitable quantum state has
hitherto remained mostly unsolved. Here, we show that already a single
dissipatively driven auxiliary particle can efficiently prepare the quantum
simulator in a low-energy state of largely arbitrary Hamiltonians. We
demonstrate the scalability of our approach and show that it is robust against
unwanted sources of decoherence. While our initialization protocol is largely
independent of the physical realization of the simulation device, we provide an
implementation example for a trapped ion quantum simulator.
