[Bugfixes] Solving some issues for qemulator MPS release (#73)

* Added angles vs angle parameter handling to hybrid_engine_old

* The reset methods in simulators must return self.

* If import fails, create dummy NoneType simulator

* Updated bindings of CoinToss

* Removed filter of simulation parameters, since it is not necessary

* Using a more sensible import approach in the test file

* Debug message converted to info message.

Author: PabloAndresCQ

python/pecos/engines/hybrid_engine_old.py

@@ -214,6 +214,12 @@ def run_gate(state, output, symbol: str, locations, **params):
 
         if params.get("simulate_gate", True):
             for location in locations:
+
+                if params.get("angles") and len(params["angles"]) == 1:
+                    params.update({"angle": params["angles"][0]})
+                elif "angle" in params and "angles" not in params:
+                    params["angles"] = (params["angle"],)
+
                 try:
                     result = state.bindings[symbol](state, location, **params)
                 except KeyError:

python/pecos/simulators/__init__.py

@@ -30,19 +30,19 @@
 
     from pecos.simulators.projectq.state import ProjectQSim  # wrapper for ProjectQ sim
 except ImportError:
-    pass
+    ProjectQSim = None
 
 # Attempt to import optional Qulacs package
-try:  # noqa: SIM105
+try:
     from pecos.simulators.qulacs.state import Qulacs  # wrapper for Qulacs sim
 except ImportError:
-    pass
+    Qulacs = None
 
 # Attempt to import optional QuEST package
-try:  # noqa: SIM105
+try:
     from pecos.simulators.quest.state import QuEST  # wrapper for QuEST sim
 except ImportError:
-    pass
+    QuEST = None
 
 # Attempt to import optional cuquantum and cupy packages
 try:
@@ -52,4 +52,5 @@
     from pecos.simulators.custatevec.state import CuStateVec  # wrapper for cuQuantum's cuStateVec
     from pecos.simulators.mps_pytket import MPS  # MPS implementation from pytket-cutensornet
 except ImportError:
-    pass
+    CuStateVec = None
+    MPS = None

python/pecos/simulators/cointoss/bindings.py

@@ -16,7 +16,17 @@
 
 gate_dict = {
     "Init": ignore_gate,
+    "Init +Z": ignore_gate,
+    "Init -Z": ignore_gate,
+    "init |0>": ignore_gate,
+    "init |1>": ignore_gate,
+    "leak": ignore_gate,
+    "leak |0>": ignore_gate,
+    "leak |1>": ignore_gate,
+    "unleak |0>": ignore_gate,
+    "unleak |1>": ignore_gate,
     "Measure": measure,
+    "measure Z": measure,
     "I": ignore_gate,
     "X": ignore_gate,
     "Y": ignore_gate,
@@ -25,12 +35,19 @@
     "RY": ignore_gate,
     "RZ": ignore_gate,
     "R1XY": ignore_gate,
+    "RXY1Q": ignore_gate,
     "SX": ignore_gate,
     "SXdg": ignore_gate,
+    "SqrtX": ignore_gate,
+    "SqrtXd": ignore_gate,
     "SY": ignore_gate,
     "SYdg": ignore_gate,
+    "SqrtY": ignore_gate,
+    "SqrtYd": ignore_gate,
     "SZ": ignore_gate,
     "SZdg": ignore_gate,
+    "SqrtZ": ignore_gate,
+    "SqrtZd": ignore_gate,
     "H": ignore_gate,
     "F": ignore_gate,
     "Fdg": ignore_gate,
@@ -48,6 +65,7 @@
     "SYY": ignore_gate,
     "SYYdg": ignore_gate,
     "SZZ": ignore_gate,
+    "SqrtZZ": ignore_gate,
     "SZZdg": ignore_gate,
     "SWAP": ignore_gate,
 }

python/pecos/simulators/cointoss/state.py

@@ -48,3 +48,8 @@ def __init__(self, num_qubits, prob=0.5, seed=None):
         self.bindings = bindings.gate_dict
         self.num_qubits = num_qubits
         self.prob = prob
+
+    def reset(self):
+        """Reset the quantum state for another run without reinitializing."""
+        # Do nothing, this simulator does not keep a state!
+        return self

python/pecos/simulators/mps_pytket/state.py

@@ -60,11 +60,12 @@ def __init__(self, num_qubits, **mps_params) -> None:
         # Initialise the MPS on state |0>
         self.reset()
 
-    def reset(self) -> None:
+    def reset(self) -> StateTN:
         """Reset the quantum state to all 0 for another run."""
         qubits = [Qubit(q) for q in range(self.num_qubits)]
         self.mps = MPSxGate(self.libhandle, qubits, self.config)
-        self.mps._logger.debug("Resetting MPS...")  # noqa: SLF001
+        self.mps._logger.info("Resetting MPS...")  # noqa: SLF001
+        return self
 
     def __del__(self) -> None:
         # CuPy will release GPU memory when the variable ``self.mps`` is no longer

python/pecos/simulators/quantum_simulator.py

@@ -46,23 +46,7 @@ def __init__(self, backend: str | object | None = None, **params) -> None:
         self.num_qubits = None
         self.state = None
         self.backend = backend
-
-        if backend in {"MPS", "mps"}:
-            self.qsim_params = {
-                k: v
-                for k, v in params.items()
-                if k
-                in {
-                    "chi",
-                    "truncation_fidelity",
-                    "float_precision",
-                    "value_of_zero",
-                    "loglevel",
-                    "seed",
-                }
-            }  # These are listed in the docs for ``Config`` of pytket-cutensornet
-        else:
-            self.qsim_params = {}
+        self.qsim_params = params
 
     def reset(self):
         self.num_qubits = None

tests/integration/state_sim_tests/test_statevec.py

@@ -19,72 +19,34 @@
     from pecos.simulators.sim_class_types import StateVector
 
 import json
-from importlib.metadata import version
 from pathlib import Path
 
 import numpy as np
 import pytest
-from packaging.version import parse as vparse
 from pecos.circuits import QuantumCircuit
 from pecos.engines.hybrid_engine import HybridEngine
 from pecos.error_models.generic_error_model import GenericErrorModel
-from pecos.simulators import BasicSV
-
-# Try to import the requirements for Qulacs
-try:
-    from pecos.simulators import Qulacs
-
-    qulacs_ready = True
-except ImportError:
-    qulacs_ready = False
-
-# Try to import the requirements for QuEST
-try:
-    from pecos.simulators import QuEST
-
-    quest_ready = True
-except ImportError:
-    quest_ready = False
-
-# Try to import the requirements for CuStateVec
-try:
-    import cuquantum
-
-    imported_cuquantum = vparse(cuquantum._version.__version__) >= vparse("24.03.0")  # noqa: SLF001
-    import cupy as cp  # noqa: F401
-
-    imported_cupy = vparse(version("cupy")) >= vparse("10.4.0")
-    from pecos.simulators import CuStateVec
-
-    custatevec_ready = imported_cuquantum and imported_cupy
-except (ImportError, AttributeError):
-    custatevec_ready = False
-
-# Try to import pytket-cutensornet
-try:
-    import pytket.extensions.cutensornet  # noqa: F401
-    from pecos.simulators import MPS
+from pecos.simulators import (
+    MPS,
+    BasicSV,
+    CuStateVec,
+    QuEST,
+    Qulacs,
+)
 
-    mps_ready = imported_cuquantum and imported_cupy  # Same requirements as CuStateVec
-except ImportError:
-    mps_ready = False
+str_to_sim = {
+    "BasicSV": BasicSV,
+    "Qulacs": Qulacs,
+    "QuEST": QuEST,
+    "CuStateVec": CuStateVec,
+    "MPS": MPS,
+}
 
 
 def check_dependencies(simulator) -> Callable[[int], StateVector]:
-    if simulator == "BasicSV":
-        sim = BasicSV
-    elif simulator == "Qulacs" and qulacs_ready:
-        sim = Qulacs
-    elif simulator == "QuEST" and quest_ready:
-        sim = QuEST
-    elif simulator == "CuStateVec" and custatevec_ready:
-        sim = CuStateVec
-    elif simulator == "MPS" and mps_ready:
-        sim = MPS
-    else:
+    if simulator not in str_to_sim or str_to_sim[simulator] is None:
         pytest.skip(f"Requirements to test {simulator} are not met.")
-
-    return sim
+    return str_to_sim[simulator]
 
 
 def verify(simulator, qc: QuantumCircuit, final_vector: np.ndarray) -> None: