Fix naming of sqrt(iswap) gate constants (#4051)

* Rename SQRT_ISWAP_PARAMETERS

* Fix serialization tests and do further renaming.

cirq-google/cirq_google/__init__.py

@@ -32,7 +32,7 @@
     PhasedFSimEngineSimulator,
     XEBPhasedFSimCalibrationOptions,
     XEBPhasedFSimCalibrationRequest,
-    SQRT_ISWAP_PARAMETERS,
+    SQRT_ISWAP_INV_PARAMETERS,
     THETA_ZETA_GAMMA_FLOQUET_PHASED_FSIM_CHARACTERIZATION,
     make_zeta_chi_gamma_compensation_for_moments,
     make_zeta_chi_gamma_compensation_for_operations,

cirq-google/cirq_google/calibration/__init__.py

@@ -26,7 +26,7 @@
     PhasedFSimCharacterization,
     XEBPhasedFSimCalibrationOptions,
     XEBPhasedFSimCalibrationRequest,
-    SQRT_ISWAP_PARAMETERS,
+    SQRT_ISWAP_INV_PARAMETERS,
     THETA_ZETA_GAMMA_FLOQUET_PHASED_FSIM_CHARACTERIZATION,
     WITHOUT_CHI_FLOQUET_PHASED_FSIM_CHARACTERIZATION,
     merge_matching_results,

cirq-google/cirq_google/calibration/engine_simulator.py

@@ -42,7 +42,7 @@
     PhasedFSimCalibrationRequest,
     PhasedFSimCalibrationResult,
     PhasedFSimCharacterization,
-    SQRT_ISWAP_PARAMETERS,
+    SQRT_ISWAP_INV_PARAMETERS,
     try_convert_sqrt_iswap_to_fsim,
 )
 
@@ -124,7 +124,7 @@ def sample_gate(_1: Qid, _2: Qid, gate: FSimGate) -> PhasedFSimCharacterization:
     @classmethod
     def create_with_random_gaussian_sqrt_iswap(
         cls,
-        mean: PhasedFSimCharacterization = SQRT_ISWAP_PARAMETERS,
+        mean: PhasedFSimCharacterization = SQRT_ISWAP_INV_PARAMETERS,
         *,
         simulator: Optional[Simulator] = None,
         sigma: PhasedFSimCharacterization = PhasedFSimCharacterization(
@@ -228,7 +228,7 @@ def sample_gate(a: Qid, b: Qid, gate: FSimGate) -> PhasedFSimCharacterization:
                     pair_parameters = PhasedFSimCharacterization(**pair_parameters)
                 pair_parameters = pair_parameters.parameters_for_qubits_swapped()
             elif ideal_when_missing_gate:
-                pair_parameters = SQRT_ISWAP_PARAMETERS
+                pair_parameters = SQRT_ISWAP_INV_PARAMETERS
             else:
                 raise ValueError(f'Missing parameters for pair {(a, b)}')
 
@@ -238,7 +238,7 @@ def sample_gate(a: Qid, b: Qid, gate: FSimGate) -> PhasedFSimCharacterization:
                         f'Missing parameter value for pair {(a, b)}, '
                         f'parameters={pair_parameters}'
                     )
-                pair_parameters = pair_parameters.merge_with(SQRT_ISWAP_PARAMETERS)
+                pair_parameters = pair_parameters.merge_with(SQRT_ISWAP_INV_PARAMETERS)
 
             return pair_parameters
 

cirq-google/cirq_google/calibration/engine_simulator_test.py

@@ -9,7 +9,7 @@
 import cirq_google
 from cirq_google.calibration.engine_simulator import (
     PhasedFSimEngineSimulator,
-    SQRT_ISWAP_PARAMETERS,
+    SQRT_ISWAP_INV_PARAMETERS,
 )
 from cirq_google.calibration import (
     FloquetPhasedFSimCalibrationOptions,
@@ -23,7 +23,7 @@
 import cirq
 
 
-class TestPhasedFSimCalibrationRequest(PhasedFSimCalibrationRequest):
+class DummyPhasedFSimCalibrationRequest(PhasedFSimCalibrationRequest):
     def to_calibration_layer(self) -> cirq_google.CalibrationLayer:
         return NotImplemented
 
@@ -33,7 +33,7 @@ def parse_result(self, result: cirq_google.CalibrationResult) -> PhasedFSimCalib
 
 def test_test_calibration_request():
     a, b = cirq.LineQubit.range(2)
-    request = TestPhasedFSimCalibrationRequest(
+    request = DummyPhasedFSimCalibrationRequest(
         gate=cirq.FSimGate(np.pi / 4, 0.5),
         pairs=((a, b),),
         options=ALL_ANGLES_FLOQUET_PHASED_FSIM_CHARACTERIZATION,
@@ -104,7 +104,7 @@ def test_floquet_get_calibrations_when_invalid_request_fails() -> None:
     with pytest.raises(ValueError):
         engine_simulator.get_calibrations(
             [
-                TestPhasedFSimCalibrationRequest(
+                DummyPhasedFSimCalibrationRequest(
                     gate=cirq.FSimGate(np.pi / 4, 0.5),
                     pairs=((a, b),),
                     options=ALL_ANGLES_FLOQUET_PHASED_FSIM_CHARACTERIZATION,
@@ -164,7 +164,7 @@ def test_ideal_sqrt_iswap_simulates_correctly_invalid_circuit_fails() -> None:
 
 def test_with_random_gaussian_sqrt_iswap_simulates_correctly() -> None:
     engine_simulator = PhasedFSimEngineSimulator.create_with_random_gaussian_sqrt_iswap(
-        mean=SQRT_ISWAP_PARAMETERS,
+        mean=SQRT_ISWAP_INV_PARAMETERS,
         sigma=PhasedFSimCharacterization(theta=0.02, zeta=0.05, chi=0.05, gamma=None, phi=0.02),
     )
 
@@ -217,7 +217,7 @@ def test_with_random_gaussian_runs_correctly() -> None:
 
     simulator = cirq.Simulator()
     engine_simulator = PhasedFSimEngineSimulator.create_with_random_gaussian_sqrt_iswap(
-        SQRT_ISWAP_PARAMETERS, simulator=simulator
+        SQRT_ISWAP_INV_PARAMETERS, simulator=simulator
     )
 
     actual = engine_simulator.run(circuit, repetitions=20000).measurements['z']
@@ -319,12 +319,12 @@ def test_from_dictionary_sqrt_iswap_ideal_when_missing_simulates_correctly() ->
             [cirq.X(a), cirq.X(c)],
             [
                 cirq.PhasedFSimGate(**parameters_ab.asdict()).on(a, b),
-                cirq.PhasedFSimGate(**SQRT_ISWAP_PARAMETERS.asdict()).on(c, d),
+                cirq.PhasedFSimGate(**SQRT_ISWAP_INV_PARAMETERS.asdict()).on(c, d),
             ],
             [
-                cirq.PhasedFSimGate(**parameters_bc.merge_with(SQRT_ISWAP_PARAMETERS).asdict()).on(
-                    b, c
-                )
+                cirq.PhasedFSimGate(
+                    **parameters_bc.merge_with(SQRT_ISWAP_INV_PARAMETERS).asdict()
+                ).on(b, c)
             ],
         ]
     )

cirq-google/cirq_google/calibration/phased_fsim.py

@@ -213,7 +213,7 @@ def override_by(self, other: 'PhasedFSimCharacterization') -> 'PhasedFSimCharact
         return other.merge_with(self)
 
 
-SQRT_ISWAP_PARAMETERS = PhasedFSimCharacterization(
+SQRT_ISWAP_INV_PARAMETERS = PhasedFSimCharacterization(
     theta=np.pi / 4, zeta=0.0, chi=0.0, gamma=0.0, phi=0.0
 )