1.13 - CPHASE & CZ QPU Instruction

The lecture slides are available here Download here.

In the lecture, we begin with a recap of the PHASE(θ) operation on single-qubit systems, emphasizing the rotation of the relative phase in circle notation. We then introduce the CPHASE operation, which selectively rotates qubit states when certain control conditions are met. Notably, CPHASE exhibits symmetry between control and target qubits, offering flexibility in its application. The lecture concludes by showing how CZ can be constructed using HAD and CNOT operations.

Attention: Slide 4 circle notation for CPHASE on 0x1 is wrong in the video (the slides have the correct circle notation). Thanks to Lino Severin Hofstetter for pointing this out. It should be:

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And specifically for the example on page 4:

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