  Synthetic spin-orbit coupling (SOC) in controlled quantum systems such as
cold atoms or trapped ions has been of great interest. Here we show, both
theoretically and computationally, a simplest realization of SOC using
two-level cold atoms interacting with only one laser beam. The underlying
mechanism is based upon the non-adiabatic nature of laser-atom interaction,
with the Rabi frequency and atom's kinetic energy being comparable to each
other. We use the Zitterbewegung (ZB) oscillation to further illustrate the
effects of the synthesized SOC on the quantum dynamics of the two-level cold
atoms. We expect our proposal to be of experimental interest in quantum
simulation of SOC-related physics.
