Demonstrating quantum computing with the quark model

The use of quantum computing to solve a problem in quantum mechanics is illustrated, step by step, by calculating energies and transition amplitudes in a nonrelativistic quark model. The quantum computations feature the use of variational quantum imaginary time evolution implemented using automatic differentiation to determine ground and excited states of charmonium. The calculation of transition amplitudes is illustrated utilizing the Hadamard test. Examples of readout and gate error mitigation are included.