# new_cpmg_sequence¶

qctrlopencontrols.new_cpmg_sequence(duration, offset_count, pre_post_rotation=False, name=None)[source]

Creates the Carr-Purcell-Meiboom-Gill sequence.

Parameters
• duration (float) – Total duration of the sequence $$\tau$$ (in seconds).

• offset_count (int) – Number of offsets $$n$$.

• pre_post_rotation (bool, optional) – If True, a $$X_{\pi/2}$$ rotation is added at the start and end of the sequence. Defaults to False.

• name (string, optional) – Name of the sequence. Defaults to None.

Returns

The Carr-Purcell-Meiboom-Gill sequence.

Return type

DynamicDecouplingSequence

Notes

The Carr-Purcell-Meiboom-Gill sequence 1 has the same timing and number of offsets as the Carr-Purcell sequence. However, the intermediate $$\pi$$ rotations are applied along the $$Y$$ axis. That is, it consists of $$Y_{\pi}$$ operations applied at times

$t_i = \frac{\tau}{n} \left(i - \frac{1}{2}\right) \;,$

where $$i = 1, \cdots, n$$.

References

1

S. Meiboom and D. Gill, Review of Scientific Instruments 29:8, 688 (1958).