Renyi Chen

Implement dynamical decoupling.

2

Add dynamical decoupling operations to circuits for idle moments. Two methods are provided to apply dynamical decoupling. 1. Schema "XX_PAIR" and "YY_PAIR" are provided. 2. Users can provide their own...

Implement dynamical decoupling transformer

4

**Enable dynamical decoupling operations insertion** **Acceptance criteria - Users are able to use the transformer to insert dynamical decoupling sequences based on their preferences**

**Description of the issue** Test cases ``` ( cirq.PhasedXPowGate(phase_exponent=1.5, exponent=1.0), cirq.PhasedXPowGate(phase_exponent=0.5, exponent=1.0), True, ), (cirq.XPowGate(exponent=2.0), cirq.I, True), ``` should pass the [test suite](https://github.com/quantumlib/Cirq/blob/e1b03ef63af4270d6a185df3db6e43c8232c6a71/cirq-core/cirq/ops/gate_operation_test.py#L327) IIUC? If I apply `equal_up_to_global_phase` to matrices...

Multi-moment CZ, CPhase GaugeTransformers.

4

Usage: use CZGaugeTransformerMM (CZ only) / CPhaseGaugeTransformerMM (CZ+CPhase) Example: ``` Input: ┌──┐ 0: ───@────@─────H───@───@───@─── │ │ │ │ │ 1: ───@────┼@────────@───@───@─── ││ 2: ───@────@┼────────@───@───@─── │ │ │ │ │ 3:...

PauliString.after() crashes for Clifford gate PhXZ(a=0.25,x=-1,z=0) in _decompose_into_cliffords

10

**Description of the issue** PauliString.after() should be able to return a PauliString with Clifford ops input, but failed for the Clifford gate `PhasedXZGate(axis_phase_exponent=0.25, x_exponent=-1,z_exponent=0)`. **How to reproduce the issue** ```...

Order of tags: should TaggedOperation(op, "tag1", "tag2")==TaggedOperation(op, "tag2", "tag1")?

2

Now `TaggedOperation(op, "tag1", "tag2")!=TaggedOperation(op, "tag2", "tag1")` and `TaggedOperation(op, "tag1", "tag2")==TaggedOperation(op, "tag1", "tag2")` wonder why does the order of tags matter? if not, should serialization/deserialization take tag sorting into consideration?