def ms(rads: float) -> ops.XXPowGate:
"""The Mølmer–Sørensen gate, a native two-qubit operation in ion traps.
A rotation around the XX axis in the two-qubit bloch sphere.
The gate implements the following unitary:
exp(-i t XX) = [ cos(t) 0 0 -isin(t)]
[ 0 cos(t) -isin(t) 0 ]
[ 0 -isin(t) cos(t) 0 ]
[-isin(t) 0 0 cos(t) ]
Args:
rads: The rotation angle in radians.
Returns:
Mølmer–Sørensen gate rotating by the desired amount.
"""
return ops.XXPowGate(exponent=rads * 2 / np.pi, global_shift=-0.5)
def _translate_two_qubit_braket_instruction_to_cirq_operation(
instr: Instruction, ) -> List["cirq.Operation"]:
"""Converts the two-qubit braket instruction to Cirq.
Args:
instr: Two-qubit Braket instruction to convert.
Raises:
ValueError: If the instruction cannot be converted to Cirq.
"""
qubits = [LineQubit(int(qubit)) for qubit in instr.target]
gate = instr.operator
# Two-qubit non-parameterized gates.
if isinstance(gate, braket_gates.CNot):
return [cirq_ops.CNOT.on(*qubits)]
elif isinstance(gate, braket_gates.Swap):
return [cirq_ops.SWAP.on(*qubits)]
elif isinstance(gate, braket_gates.ISwap):
return [cirq_ops.ISWAP.on(*qubits)]
elif isinstance(gate, braket_gates.CZ):
return [cirq_ops.CZ.on(*qubits)]
elif isinstance(gate, braket_gates.CY):
return [
cirq_ops.S.on(qubits[1])**-1,
cirq_ops.CNOT.on(*qubits),
cirq_ops.S.on(qubits[1]),
]
# Two-qubit parameterized gates.
elif isinstance(gate, braket_gates.PSwap):
raise ValueError # TODO.
elif isinstance(gate, braket_gates.CPhaseShift):
return [cirq_ops.CZ.on(*qubits)**(gate.angle / np.pi)]
elif isinstance(gate, braket_gates.CPhaseShift00):
raise ValueError # TODO.
elif isinstance(gate, braket_gates.CPhaseShift01):
raise ValueError # TODO.
elif isinstance(gate, braket_gates.CPhaseShift10):
raise ValueError # TODO.
elif isinstance(gate, braket_gates.XX):
return [
cirq_ops.XXPowGate(exponent=gate.angle / np.pi,
global_shift=-0.5).on(*qubits)
]
elif isinstance(gate, braket_gates.YY):
return [
cirq_ops.YYPowGate(exponent=gate.angle / np.pi,
global_shift=-0.5).on(*qubits)
]
elif isinstance(gate, braket_gates.ZZ):
return [
cirq_ops.ZZPowGate(exponent=gate.angle / np.pi,
global_shift=-0.5).on(*qubits)
]
elif isinstance(gate, braket_gates.XY):
return [cirq_ops.ISwapPowGate(exponent=gate.angle / np.pi).on(*qubits)]
else:
raise ValueError(
f"Unable to convert the instruction {instr} to Cirq. If you think "
"this is a bug, you can open an issue on the Mitiq GitHub at "
"https://github.com/unitaryfund/mitiq.")
cirq_circuit = Circuit(uncommon_gate.on(LineQubit(0)))
test_circuit = from_braket(to_braket(cirq_circuit))
testing.assert_allclose_up_to_global_phase(
protocols.unitary(test_circuit),
protocols.unitary(cirq_circuit),
atol=1e-7,
)
@pytest.mark.parametrize(
"common_gate",
[
ops.CNOT,
ops.CZ,
ops.ISWAP,
ops.XXPowGate(exponent=-0.2),
ops.YYPowGate(exponent=0.3),
ops.ZZPowGate(exponent=-0.1),
],
)
def test_to_from_braket_common_two_qubit_gates(common_gate):
"""These gates should stay the same (i.e., not get decomposed) when
converting Cirq -> Braket -> Cirq.
"""
cirq_circuit = Circuit(common_gate.on(*LineQubit.range(2)))
test_circuit = from_braket(to_braket(cirq_circuit))
testing.assert_allclose_up_to_global_phase(
protocols.unitary(test_circuit),
protocols.unitary(cirq_circuit),
atol=1e-7,
)
def _translate_two_qubit_braket_instruction_to_cirq_operation(
instr: Instruction,
) -> List["cirq.Operation"]:
"""Converts the two-qubit braket instruction to Cirq.
Args:
instr: Two-qubit Braket instruction to convert.
Raises:
ValueError: If the instruction cannot be converted to Cirq.
"""
qubits = [LineQubit(int(qubit)) for qubit in instr.target]
gate = instr.operator
# Two-qubit non-parameterized gates.
if isinstance(gate, braket_gates.CNot):
return [cirq_ops.CNOT.on(*qubits)]
elif isinstance(gate, braket_gates.Swap):
return [cirq_ops.SWAP.on(*qubits)]
elif isinstance(gate, braket_gates.ISwap):
return [cirq_ops.ISWAP.on(*qubits)]
elif isinstance(gate, braket_gates.CZ):
return [cirq_ops.CZ.on(*qubits)]
elif isinstance(gate, braket_gates.CY):
return [
cirq_ops.S.on(qubits[1]) ** -1,
cirq_ops.CNOT.on(*qubits),
cirq_ops.S.on(qubits[1]),
]
# Two-qubit parameterized gates.
elif isinstance(gate, braket_gates.CPhaseShift):
return [cirq_ops.CZ.on(*qubits) ** (gate.angle / np.pi)]
elif isinstance(gate, braket_gates.CPhaseShift00):
return [
cirq_ops.XX(*qubits),
cirq_ops.CZ.on(*qubits) ** (gate.angle / np.pi),
cirq_ops.XX(*qubits),
]
elif isinstance(gate, braket_gates.CPhaseShift01):
return [
cirq_ops.X(qubits[0]),
cirq_ops.CZ.on(*qubits) ** (gate.angle / np.pi),
cirq_ops.X(qubits[0]),
]
elif isinstance(gate, braket_gates.CPhaseShift10):
return [
cirq_ops.X(qubits[1]),
cirq_ops.CZ.on(*qubits) ** (gate.angle / np.pi),
cirq_ops.X(qubits[1]),
]
elif isinstance(gate, braket_gates.PSwap):
return [
cirq_ops.SWAP.on(*qubits),
cirq_ops.CNOT.on(*qubits),
cirq_ops.Z.on(qubits[1]) ** (gate.angle / np.pi),
cirq_ops.CNOT.on(*qubits),
]
elif isinstance(gate, braket_gates.XX):
return [
cirq_ops.XXPowGate(
exponent=gate.angle / np.pi, global_shift=-0.5
).on(*qubits)
]
elif isinstance(gate, braket_gates.YY):
return [
cirq_ops.YYPowGate(
exponent=gate.angle / np.pi, global_shift=-0.5
).on(*qubits)
]
elif isinstance(gate, braket_gates.ZZ):
return [
cirq_ops.ZZPowGate(
exponent=gate.angle / np.pi, global_shift=-0.5
).on(*qubits)
]
elif isinstance(gate, braket_gates.XY):
return [cirq_ops.ISwapPowGate(exponent=gate.angle / np.pi).on(*qubits)]
else:
_raise_braket_to_cirq_error(instr)