def default_compilation_pass(self, optimisation_level: int = 1) -> BasePass:
"""
A suggested compilation pass that will guarantee the resulting circuit
will be suitable to run on this backend with as few preconditions as
possible.
:param optimisation_level: The level of optimisation to perform during
compilation. Level 0 just solves the device constraints without
optimising. Level 1 additionally performs some light optimisations.
Level 2 adds more intensive optimisations that can increase compilation
time for large circuits. Defaults to 1.
:type optimisation_level: int, optional
:return: Compilation pass guaranteeing required predicates.
:rtype: BasePass
"""
assert optimisation_level in range(3)
cx_circ = Circuit(2)
cx_circ.Sdg(0)
cx_circ.V(1)
cx_circ.Sdg(1)
cx_circ.Vdg(1)
cx_circ.add_gate(OpType.ZZMax, [0, 1])
cx_circ.Vdg(1)
cx_circ.Sdg(1)
cx_circ.add_phase(0.5)
def sq(a, b, c):
circ = Circuit(1)
if c != 0:
circ.Rz(c, 0)
if b != 0:
circ.Rx(b, 0)
if a != 0:
circ.Rz(a, 0)
return circ
rebase = RebaseCustom({OpType.ZZMax}, cx_circ,
{OpType.Rx, OpType.Ry, OpType.Rz}, sq)
squash = SquashCustom({OpType.Rz, OpType.Rx, OpType.Ry}, sq)
seq = [DecomposeBoxes()] # Decompose boxes into basic gates
if optimisation_level == 1:
seq.append(SynthesiseIBM()) # Optional fast optimisation
elif optimisation_level == 2:
seq.append(FullPeepholeOptimise()) # Optional heavy optimisation
seq.append(rebase) # Map to target gate set
if optimisation_level != 0:
seq.append(
squash) # Optionally simplify 1qb gate chains within this gate set
return SequencePass(seq)
def pauli_measurement(pauli_string:Iterable[Tuple[int,str]], circ:Circuit) :
"""Appends measurement instructions to a given circuit, measuring each qubit in a given basis
:param pauli_string: The pauli operator to measure, as tuples of pauli name and qubit.
:type pauli_string: Iterable[Tuple[int,str]]
:param circ: Circuit to add measurement to.
:type circ: Circuit
"""
measured_qbs = []
for qb_idx, p in pauli_string:
measured_qbs.append(qb_idx)
if p=='X':
circ.H(qb_idx)
elif p=='Y':
circ.Sdg(qb_idx)
circ.H(qb_idx)
for idx in measured_qbs:
circ.Measure(idx, idx)
