The development of quantum technology over the last few decades has opened new pathways to solving more complex computational problems. While the goal of a universal, fault-tolerant quantum computer is still out of reach, success has been found with modelling quantum chemical systems with analog quantum simulators. Analog quantum simulators are dedicated devices restricted to simulating a limited class of quantum systems: the evolution of the desired quantum system is mapped onto the controlled evolution of the simulator.

Developing an algorithm for rotational motion lays the foundation for modelling more complex dynamics, such as coupling between rotational and vibrational modes. This phenomenon, known as Coriolis coupling, is crucial in computing accurate rovibrational spectra, which are used to identify molecules present in the interstellar medium. Classical methods are limited by requiring numerical approximations or high-quality experimental spectra to use as refinement data.

We have developed the first quantum algorithm for the simulation of rigid rotors. Our algorithm is adapted for present-day quantum simulators by using two vibrational modes to represent rotational modes. We show that our algorithm can produce accurate rotational spectra for different types of rigid rotors. This allows for the addition of vibrational modes for exact computation of Coriolis coupling. Future work includes using a non-rigid rotor model, which will allow for simulation of floppy molecules with more complex internal dynamics.