Add generic analog circuit builder class

cirq-google/cirq_google/__init__.py

@@ -64,6 +64,7 @@
     PhysicalZTag as PhysicalZTag,
     SYC as SYC,
     SycamoreGate as SycamoreGate,
+    WaitGateWithUnit as WaitGateWithUnit,
     WILLOW as WILLOW,
     WillowGate as WillowGate,
 )

cirq-google/cirq_google/experimental/analog_experiments/__init__.py

@@ -18,3 +18,7 @@
     FrequencyMap as FrequencyMap,
     AnalogTrajectory as AnalogTrajectory,
 )
+
+from cirq_google.experimental.analog_experiments.generic_analog_circuit import (
+    GenericAnalogCircuitBuilder as GenericAnalogCircuitBuilder,
+)

cirq-google/cirq_google/experimental/analog_experiments/analog_trajectory_util.py

@@ -36,11 +36,13 @@ class FrequencyMap:
         duration: duration of step
         qubit_freqs: dict describing qubit frequencies at end of step (None if idle)
         couplings: dict describing coupling rates at end of step
+        is_wait_step: a bool indicating only wait gate should be added.
     """
 
     duration: su.ValueOrSymbol
     qubit_freqs: dict[str, su.ValueOrSymbol | None]
     couplings: dict[tuple[str, str], su.ValueOrSymbol]
+    is_wait_step: bool
 
     def _is_parameterized_(self) -> bool:
         return (
@@ -68,6 +70,7 @@ def _resolve_parameters_(
             couplings={
                 k: su.direct_symbol_replacement(v, resolver_) for k, v in self.couplings.items()
             },
+            is_wait_step=self.is_wait_step,
         )
 
 
@@ -129,9 +132,11 @@ def from_sparse_trajectory(
         full_trajectory: list[FrequencyMap] = []
         init_qubit_freq_dict: dict[str, tu.Value | None] = {q: None for q in qubits}
         init_g_dict: dict[tuple[str, str], tu.Value] = {p: 0 * tu.MHz for p in pairs}
-        full_trajectory.append(FrequencyMap(0 * tu.ns, init_qubit_freq_dict, init_g_dict))
+        full_trajectory.append(FrequencyMap(0 * tu.ns, init_qubit_freq_dict, init_g_dict, False))
 
         for dt, qubit_freq_dict, g_dict in sparse_trajectory:
+            # When both qubit_freq_dict and g_dict is empty, it is a wait step.
+            is_wait_step = not (qubit_freq_dict or g_dict)
             # If no freq provided, set equal to previous
             new_qubit_freq_dict = {
                 q: qubit_freq_dict.get(q, full_trajectory[-1].qubit_freqs.get(q)) for q in qubits
@@ -141,7 +146,7 @@ def from_sparse_trajectory(
                 p: g_dict.get(p, full_trajectory[-1].couplings.get(p)) for p in pairs  # type: ignore[misc]
             }
 
-            full_trajectory.append(FrequencyMap(dt, new_qubit_freq_dict, new_g_dict))
+            full_trajectory.append(FrequencyMap(dt, new_qubit_freq_dict, new_g_dict, is_wait_step))
         return cls(full_trajectory=full_trajectory, qubits=qubits, pairs=pairs)
 
     def get_full_trajectory_with_resolved_idles(

cirq-google/cirq_google/experimental/analog_experiments/analog_trajectory_util_test.py

@@ -26,6 +26,7 @@ def freq_map() -> atu.FrequencyMap:
         10 * tu.ns,
         {"q0_0": 5 * tu.GHz, "q0_1": 6 * tu.GHz, "q0_2": sympy.Symbol("f_q0_2")},
         {("q0_0", "q0_1"): 5 * tu.MHz, ("q0_1", "q0_2"): sympy.Symbol("g_q0_1_q0_2")},
+        False,
     )
 
 
@@ -42,6 +43,7 @@ def test_freq_map_resolve(freq_map: atu.FrequencyMap) -> None:
         10 * tu.ns,
         {"q0_0": 5 * tu.GHz, "q0_1": 6 * tu.GHz, "q0_2": 6 * tu.GHz},
         {("q0_0", "q0_1"): 5 * tu.MHz, ("q0_1", "q0_2"): 7 * tu.MHz},
+        False,
     )
 
 
@@ -52,36 +54,47 @@ def test_freq_map_resolve(freq_map: atu.FrequencyMap) -> None:
 def sparse_trajectory() -> list[FreqMapType]:
     traj1: FreqMapType = (20 * tu.ns, {"q0_1": 5 * tu.GHz}, {})
     traj2: FreqMapType = (30 * tu.ns, {"q0_2": 8 * tu.GHz}, {})
-    traj3: FreqMapType = (
+    traj3: FreqMapType = (35 * tu.ns, {}, {})
+    traj4: FreqMapType = (
         40 * tu.ns,
         {"q0_0": 8 * tu.GHz, "q0_1": None, "q0_2": None},
         {("q0_0", "q0_1"): 5 * tu.MHz, ("q0_1", "q0_2"): 8 * tu.MHz},
     )
-    return [traj1, traj2, traj3]
+    return [traj1, traj2, traj3, traj4]
 
 
 def test_full_traj(sparse_trajectory: list[FreqMapType]) -> None:
     analog_traj = atu.AnalogTrajectory.from_sparse_trajectory(sparse_trajectory)
-    assert len(analog_traj.full_trajectory) == 4
+    assert len(analog_traj.full_trajectory) == 5
     assert analog_traj.full_trajectory[0] == atu.FrequencyMap(
         0 * tu.ns,
         {"q0_0": None, "q0_1": None, "q0_2": None},
         {("q0_0", "q0_1"): 0 * tu.MHz, ("q0_1", "q0_2"): 0 * tu.MHz},
+        False,
     )
     assert analog_traj.full_trajectory[1] == atu.FrequencyMap(
         20 * tu.ns,
         {"q0_0": None, "q0_1": 5 * tu.GHz, "q0_2": None},
         {("q0_0", "q0_1"): 0 * tu.MHz, ("q0_1", "q0_2"): 0 * tu.MHz},
+        False,
     )
     assert analog_traj.full_trajectory[2] == atu.FrequencyMap(
         30 * tu.ns,
         {"q0_0": None, "q0_1": 5 * tu.GHz, "q0_2": 8 * tu.GHz},
         {("q0_0", "q0_1"): 0 * tu.MHz, ("q0_1", "q0_2"): 0 * tu.MHz},
+        False,
     )
     assert analog_traj.full_trajectory[3] == atu.FrequencyMap(
+        35 * tu.ns,
+        {"q0_0": None, "q0_1": 5 * tu.GHz, "q0_2": 8 * tu.GHz},
+        {("q0_0", "q0_1"): 0 * tu.MHz, ("q0_1", "q0_2"): 0 * tu.MHz},
+        True,
+    )
+    assert analog_traj.full_trajectory[4] == atu.FrequencyMap(
         40 * tu.ns,
         {"q0_0": 8 * tu.GHz, "q0_1": None, "q0_2": None},
         {("q0_0", "q0_1"): 5 * tu.MHz, ("q0_1", "q0_2"): 8 * tu.MHz},
+        False,
     )
 
 
@@ -92,26 +105,36 @@ def test_get_full_trajectory_with_resolved_idles(sparse_trajectory: list[FreqMap
         {"q0_0": 5 * tu.GHz, "q0_1": 6 * tu.GHz, "q0_2": 7 * tu.GHz}
     )
 
-    assert len(resolved_full_traj) == 4
+    assert len(resolved_full_traj) == 5
     assert resolved_full_traj[0] == atu.FrequencyMap(
         0 * tu.ns,
         {"q0_0": 5 * tu.GHz, "q0_1": 6 * tu.GHz, "q0_2": 7 * tu.GHz},
         {("q0_0", "q0_1"): 0 * tu.MHz, ("q0_1", "q0_2"): 0 * tu.MHz},
+        False,
     )
     assert resolved_full_traj[1] == atu.FrequencyMap(
         20 * tu.ns,
         {"q0_0": 5 * tu.GHz, "q0_1": 5 * tu.GHz, "q0_2": 7 * tu.GHz},
         {("q0_0", "q0_1"): 0 * tu.MHz, ("q0_1", "q0_2"): 0 * tu.MHz},
+        False,
     )
     assert resolved_full_traj[2] == atu.FrequencyMap(
         30 * tu.ns,
         {"q0_0": 5 * tu.GHz, "q0_1": 5 * tu.GHz, "q0_2": 8 * tu.GHz},
         {("q0_0", "q0_1"): 0 * tu.MHz, ("q0_1", "q0_2"): 0 * tu.MHz},
+        False,
     )
     assert resolved_full_traj[3] == atu.FrequencyMap(
+        35 * tu.ns,
+        {"q0_0": 5 * tu.GHz, "q0_1": 5 * tu.GHz, "q0_2": 8 * tu.GHz},
+        {("q0_0", "q0_1"): 0 * tu.MHz, ("q0_1", "q0_2"): 0 * tu.MHz},
+        True,
+    )
+    assert resolved_full_traj[4] == atu.FrequencyMap(
         40 * tu.ns,
         {"q0_0": 8 * tu.GHz, "q0_1": 6 * tu.GHz, "q0_2": 7 * tu.GHz},
         {("q0_0", "q0_1"): 5 * tu.MHz, ("q0_1", "q0_2"): 8 * tu.MHz},
+        False,
     )
 
 

cirq-google/cirq_google/experimental/analog_experiments/generic_analog_circuit.py

@@ -0,0 +1,144 @@
+# Copyright 2025 The Cirq Developers
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import functools
+import re
+
+import cirq
+from cirq_google.experimental.analog_experiments import analog_trajectory_util as atu
+from cirq_google.ops import analog_detune_gates as adg, wait_gate as wg
+from cirq_google.study import symbol_util as su
+
+
+def _get_neighbor_freqs(
+    qubit_pair: tuple[str, str], qubit_freq_dict: dict[str, su.ValueOrSymbol | None]
+) -> tuple[su.ValueOrSymbol | None, su.ValueOrSymbol | None]:
+    """Get neighbor freqs from qubit_freq_dict given the pair."""
+    sorted_pair = sorted(qubit_pair, key=_to_grid_qubit)
+    return (qubit_freq_dict[sorted_pair[0]], qubit_freq_dict[sorted_pair[1]])
+
+
+@functools.cache
+def _to_grid_qubit(qubit_name: str) -> cirq.GridQubit:
+    match = re.compile(r"^q(\d+)_(\d+)$").match(qubit_name)
+    if match is None:
+        raise ValueError(f"Invalid qubit name format: '{qubit_name}'. Expected 'q<row>_<col>'.")
+    return cirq.GridQubit(int(match[1]), int(match[2]))
+
+
+def _coupler_name_from_qubit_pair(qubit_pair: tuple[str, str]) -> str:
+    sorted_pair = sorted(qubit_pair, key=_to_grid_qubit)
+    return f"c_{sorted_pair[0]}_{sorted_pair[1]}"
+
+
+def _get_neighbor_coupler_freqs(
+    qubit_name: str, coupler_g_dict: dict[tuple[str, str], su.ValueOrSymbol]
+) -> dict[str, su.ValueOrSymbol]:
+    """Get neighbor coupler coupling strength g given qubit name."""
+    return {
+        _coupler_name_from_qubit_pair(pair): g
+        for pair, g in coupler_g_dict.items()
+        if qubit_name in pair
+    }
+
+
+class GenericAnalogCircuitBuilder:
+    """Class for making arbitrary analog circuits. The circuit is defined by an
+    AnalogTrajectory object. The class constructs the circuit from AnalogDetune
+    pulses, which automatically calculate the necessary bias amps to both qubits
+    and couplers, using tu.Values from analog calibration whenever available.
+
+    Attributes:
+        trajectory: AnalogTrajectory object defining the circuit
+        g_ramp_shaping: coupling ramps are shaped according to ramp_shape_exp if True
+        qubits: list of qubits in the circuit
+        pairs: list of couplers in the circuit
+        ramp_shape_exp: exponent of g_ramp (g proportional to t^ramp_shape_exp)
+        interpolate_coupling_cal: interpolates between calibrated coupling tu.Values if True
+        linear_qubit_ramp: if True, the qubit ramp is linear. if false, a cosine shaped
+            ramp is used.
+    """
+
+    def __init__(
+        self,
+        trajectory: atu.AnalogTrajectory,
+        g_ramp_shaping: bool = False,
+        ramp_shape_exp: int = 1,
+        interpolate_coupling_cal: bool = False,
+        linear_qubit_ramp: bool = True,
+    ):
+        self.trajectory = trajectory
+        self.g_ramp_shaping = g_ramp_shaping
+        self.ramp_shape_exp = ramp_shape_exp
+        self.interpolate_coupling_cal = interpolate_coupling_cal
+        self.linear_qubit_ramp = linear_qubit_ramp
+
+    def make_circuit(self) -> cirq.Circuit:
+        """Assemble moments described in trajectory."""
+        prev_freq_map = self.trajectory.full_trajectory[0]
+        moments = []
+        for freq_map in self.trajectory.full_trajectory[1:]:
+            if freq_map.is_wait_step:
+                targets = [_to_grid_qubit(q) for q in self.trajectory.qubits]
+                wait_gate = wg.WaitGateWithUnit(
+                    freq_map.duration, qid_shape=cirq.qid_shape(targets)
+                )
+                moment = cirq.Moment(wait_gate.on(*targets))
+            else:
+                moment = self.make_one_moment(freq_map, prev_freq_map)
+            moments.append(moment)
+            prev_freq_map = freq_map
+
+        return cirq.Circuit.from_moments(*moments)
+
+    def make_one_moment(
+        self, freq_map: atu.FrequencyMap, prev_freq_map: atu.FrequencyMap
+    ) -> cirq.Moment:
+        """Make one moment of analog detune qubit and coupler gates given freqs."""
+        qubit_gates = []
+        for q, freq in freq_map.qubit_freqs.items():
+            qubit_gates.append(
+                adg.AnalogDetuneQubit(
+                    length=freq_map.duration,
+                    w=freq_map.duration,
+                    target_freq=freq,
+                    prev_freq=prev_freq_map.qubit_freqs.get(q),
+                    neighbor_coupler_g_dict=_get_neighbor_coupler_freqs(q, freq_map.couplings),
+                    prev_neighbor_coupler_g_dict=_get_neighbor_coupler_freqs(
+                        q, prev_freq_map.couplings
+                    ),
+                    linear_rise=self.linear_qubit_ramp,
+                ).on(_to_grid_qubit(q))
+            )
+        coupler_gates = []
+        for p, g_max in freq_map.couplings.items():
+            # Currently skipping the step if these are the same.
+            # However, change in neighbor qubit freq could potentially change coupler amp
+            if g_max == prev_freq_map.couplings[p]:
+                continue
+
+            coupler_gates.append(
+                adg.AnalogDetuneCouplerOnly(
+                    length=freq_map.duration,
+                    w=freq_map.duration,
+                    g_0=prev_freq_map.couplings[p],
+                    g_max=g_max,
+                    g_ramp_exponent=self.ramp_shape_exp,
+                    neighbor_qubits_freq=_get_neighbor_freqs(p, freq_map.qubit_freqs),
+                    prev_neighbor_qubits_freq=_get_neighbor_freqs(p, prev_freq_map.qubit_freqs),
+                    interpolate_coupling_cal=self.interpolate_coupling_cal,
+                ).on(*sorted([_to_grid_qubit(p[0]), _to_grid_qubit(p[1])]))
+            )
+
+        return cirq.Moment(qubit_gates + coupler_gates)