iqm.pulse.utils.phase_transformation

iqm.pulse.utils.phase_transformation(psi_1=0.0, psi_2=0.0)

Implement an arbitrary (RZ, PRX, RZ) gate sequence by modifying the parameters of the IQ pulse implementing the PRX.

By commutation rules we have

\[RZ(\psi_2) \: PRX(\theta, \phi) \: RZ(\psi_1) = PRX(\theta, \phi+\psi_2) \: RZ(\psi_1 + \psi_2).\]

Hence an arbitrary (RZ, PRX, RZ) gate sequence is equivalent to (RZ, PRX) with adjusted angles.

Use case: with resonant driving, the PRX gate can be implemented using an IQPulse instance, and the preceding RZ can be handled by decrementing the local oscillator phase beforehand (something the IQPulse instruction can also do), which is equivalent to rotating the local computational frame around the z axis in the opposite direction of the required quantum state rotation.

Parameters:

• psi_1 (float) – RZ angle before the PRX (in rad)

• psi_2 (float) – RZ angle after the PRX (in rad)

Returns:

change to the PRX phase angle (in rad), phase increment for the IQ pulse that implements the remaining RZ (in rad)

Return type:

tuple[float, float]