Model-insensitive control of nonlinear resonators

A system for controlling a spin system in an external magnetic field, comprising:

• a resonator configured to generate a magnetic field in response to receiving pulses from a control system, the magnetic field applied to the spin system;
• and
• the control system, coupled to the resonator and configured to perform operations comprising:
• defining a target operation to be performed on the spin system,
• generating a sequence of parameters that represent the target operation and establish a control sequence for the resonator,
• converting the control sequence into successive pairs of first and second pulses,
• sending the successive pairs of first and second pulses to the resonator by alternately,
• sending a first pulse to the resonator over a first period,
• sending a second pulse to the resonator over a second period immediately following the first period,
• wherein each first pulse maintains the magnetic field generated by the resonator in a transient state during the first period,
• wherein the resonator alters a magnitude of the generated magnetic field to zero in response to each received second pulse, and
• wherein the control sequence corresponds to a shaped pulse that:
• suppresses hysteretic effects of the resonator by driving a magnetic field produced by the resonator to zero at the beginning and end of each successive pair of first and second pulses, and
• provides control that is insensitive to variations in parameters of the resonator by maintaining the magnetic field in a transient state.