Cold-Atom Quantum Simulation of Ultrafast Dynamics*

We demonstrate a quantum simulator of ultrafast phenomena, in which time-varying forces on neutral strontium atoms in a tunable optical trap emulate the electric fields of a pulsed laser acting on electrons or nuclei in a binding potential. The simulator operates in regimes equivalent to those of ultrafast and strong-field pulsed-laser experiments, opening up an unexplored application of quantum simulation techniques and a complementary path towards investigating open questions in ultrafast science. The wide difference in energy scales between simulator and simuland gives rise to a temporal magnification factor of up to twelve orders of magnitude, simplifying experimental access to the dynamics. The correspondence with ultrafast science is demonstrated by a sequence of experiments: we perform nonlinear spectroscopy of a many-body bound state, control the excitation spectrum by shaping the potential, observe sub-cycle unbinding dynamics during a strong few-cycle pulse, and directly measure carrier-envelope phase dependence of the response to an ultrafast-equivalent pulse.