Files
final-qibotn/tests/test_cuquantum_cutensor_backend.py
2025-08-27 11:08:16 +08:00

190 lines
6.3 KiB
Python

import math
import cupy as cp
import pytest
import qibo
from qibo import construct_backend, hamiltonians
from qibo.models import QFT
from qibo.symbols import X, Z
def qibo_qft(nqubits, swaps):
circ_qibo = QFT(nqubits, swaps)
state_vec = circ_qibo().state(numpy=True)
return circ_qibo, state_vec
def build_observable(nqubits):
"""Helper function to construct a target observable."""
hamiltonian_form = 0
for i in range(nqubits):
hamiltonian_form += 0.5 * X(i % nqubits) * Z((i + 1) % nqubits)
hamiltonian = hamiltonians.SymbolicHamiltonian(form=hamiltonian_form)
return hamiltonian, hamiltonian_form
def build_observable_dict(nqubits):
"""Construct a target observable as a dictionary representation.
Returns a dictionary suitable for `create_hamiltonian_from_dict`.
"""
terms = []
for i in range(nqubits):
term = {
"coefficient": 0.5,
"operators": [("X", i % nqubits), ("Z", (i + 1) % nqubits)],
}
terms.append(term)
return {"terms": terms}
@pytest.mark.gpu
@pytest.mark.parametrize("nqubits", [1, 2, 5, 10])
def test_eval(nqubits: int, dtype="complex128"):
"""
Args:
nqubits (int): Total number of qubits in the system.
dtype (str): The data type for precision, 'complex64' for single,
'complex128' for double.
"""
# Test qibo
qibo.set_backend(backend="numpy")
qibo_circ, result_sv = qibo_qft(nqubits, swaps=True)
result_sv_cp = cp.asarray(result_sv)
# Test cutensornet
backend = construct_backend(backend="qibotn", platform="cutensornet")
# Test 1: no computation settings specified. Use default.
result_tn = backend.execute_circuit(circuit=qibo_circ)
print(
f"State vector difference: {abs(result_tn.statevector.flatten() - result_sv_cp).max():0.3e}"
)
assert cp.allclose(
result_sv_cp, result_tn.statevector.flatten()
), "Resulting dense vectors do not match"
# Test 2: Explicit computation settings specified (same as default).
computation_settings = {
"MPI_enabled": False,
"MPS_enabled": False,
"NCCL_enabled": False,
"expectation_enabled": False,
}
backend.configure_tn_simulation(computation_settings)
result_tn = backend.execute_circuit(circuit=qibo_circ)
print(
f"State vector difference: {abs(result_tn.statevector.flatten() - result_sv_cp).max():0.3e}"
)
assert cp.allclose(
result_sv_cp, result_tn.statevector.flatten()
), "Resulting dense vectors do not match"
@pytest.mark.gpu
@pytest.mark.parametrize("nqubits", [2, 5, 10])
def test_mps(nqubits: int, dtype="complex128"):
"""Evaluate MPS with cuQuantum.
Args:
nqubits (int): Total number of qubits in the system.
dtype (str): The data type for precision, 'complex64' for single,
'complex128' for double.
"""
# Test qibo
qibo.set_backend(backend="numpy")
qibo_circ, result_sv = qibo_qft(nqubits, swaps=True)
result_sv_cp = cp.asarray(result_sv)
# Test cutensornet
backend = construct_backend(backend="qibotn", platform="cutensornet")
# Test 1: No MPS computation settings specified. Use default.
computation_settings_1 = {
"MPI_enabled": False,
"MPS_enabled": True,
"NCCL_enabled": False,
"expectation_enabled": False,
}
backend.configure_tn_simulation(computation_settings_1)
result_tn = backend.execute_circuit(circuit=qibo_circ)
print(
f"State vector difference: {abs(result_tn.statevector.flatten() - result_sv_cp).max():0.3e}"
)
assert cp.allclose(
result_tn.statevector.flatten(), result_sv_cp
), "Resulting dense vectors do not match"
# Test 2: Explicit MPS computation settings specified (same as default).
computation_settings_2 = {
"MPI_enabled": False,
"MPS_enabled": {
"qr_method": False,
"svd_method": {
"partition": "UV",
"abs_cutoff": 1e-12,
},
},
"NCCL_enabled": False,
"expectation_enabled": False,
}
backend.configure_tn_simulation(computation_settings_2)
result_tn = backend.execute_circuit(circuit=qibo_circ)
print(
f"State vector difference: {abs(result_tn.statevector.flatten() - result_sv_cp).max():0.3e}"
)
assert cp.allclose(
result_tn.statevector.flatten(), result_sv_cp
), "Resulting dense vectors do not match"
@pytest.mark.parametrize("nqubits", [2, 5, 10])
def test_expectation(nqubits: int, dtype="complex128"):
# Test qibo
qibo_circ, state_vec_qibo = qibo_qft(nqubits, swaps=True)
ham, ham_form = build_observable(nqubits)
numpy_backend = construct_backend("numpy")
exact_expval = numpy_backend.calculate_expectation_state(
hamiltonian=ham,
state=state_vec_qibo,
normalize=False,
)
# Test cutensornet
backend = construct_backend(backend="qibotn", platform="cutensornet")
# Test 1: No Hamilitonian computation settings specified. Use default.
computation_settings_1 = {
"MPI_enabled": False,
"MPS_enabled": False,
"NCCL_enabled": False,
"expectation_enabled": True,
}
backend.configure_tn_simulation(computation_settings_1)
result_tn = backend.execute_circuit(circuit=qibo_circ)
assert math.isclose(exact_expval.item(), result_tn.real.get().item(), abs_tol=1e-7)
# Test 2: hamiltonians.SymbolicHamiltonian object in computation settings specified.
computation_settings_2 = {
"MPI_enabled": False,
"MPS_enabled": False,
"NCCL_enabled": False,
"expectation_enabled": ham,
}
backend.configure_tn_simulation(computation_settings_2)
result_tn = backend.execute_circuit(circuit=qibo_circ)
assert math.isclose(exact_expval.item(), result_tn.real.get().item(), abs_tol=1e-7)
# Test 3: Dictionary object form of hamiltonian in computation settings specified.
ham_dict = build_observable_dict(nqubits)
computation_settings_3 = {
"MPI_enabled": False,
"MPS_enabled": False,
"NCCL_enabled": False,
"expectation_enabled": ham_dict,
}
backend.configure_tn_simulation(computation_settings_3)
result_tn = backend.execute_circuit(circuit=qibo_circ)
assert math.isclose(exact_expval.item(), result_tn.real.get().item(), abs_tol=1e-7)