def get_all_couplings(qpu_layout: QpuLayout) -> list[Coupling]:
"""
Given `qpu_layout` of `Qubit`s, return all couplings between nearest
neighbors.
Parameters
----------
qpu_layout: QpuLayout
List of `Qubit`s to use as `QpuLayout`.
Returns
-------
list[Coupling]
List of all possible couplings between nearest neighbor `Qubit`s.
Example
-------
>>> get_all_couplings(qpu_layout=((0, 0), (0, 1), (1, 0), (1, 1)))
[((0, 0), (0, 1)), ((0, 0), (1, 0)), ((0, 1), (1, 1)), ((1, 0), (1, 1))]
"""
return sort({
tuple(sort(((x1, y1), (x2, y2))))
for x1, y1 in qpu_layout for x2, y2 in qpu_layout
if x1 == x2 and abs(y1 - y2) == 1 or y1 == y2 and abs(x1 - x2) == 1
})
def isclose(self, gate: Gate, atol: float = 1e-8) -> bool:
"""
Determine if the matrix of `gate` is close within an absolute
tollerance. If the gates are acting on a different set of qubits,
`isclose` will return `False`.
Parameters
----------
gate: PowerMatrixGate
Gate to compare with.
atol: float, optional
Absolute tollerance.
Returns
-------
bool
`True` if the two gates are close withing the given absolute
tollerance, otherwise `False`.
Example
-------
>>> g1 = PowerMatrixGate(U = [[1, 2], [3, 4]])
>>> g2 = PowerMatrixGate(U = [[4, 5], [3, 4]])
>>> g1.isclose(g1)
True
>>> g1.isclose(g2)
False
>>> g1.on([3]).isclose(g1)
False
>>> g1.on([3]).isclose(g1.on([3])
True
"""
if not (self.qubits is None) ^ (gate.qubits is None):
# The gates differ if they act on a different set of qubits
if self.qubits is not None and sort(self.qubits) != sort(
gate.qubits):
return False
# Get unitaries
_U1 = self.matrix(order=self.qubits if self.qubits else None)
_U2 = gate.matrix(order=self.qubits if self.qubits else None)
# If either matrix does not exist, the two gates differ
return np.allclose(_U1, _U2, atol=atol)
else:
return False
def moments(
circuit: iter[{BaseGate, Circuit}]) -> list[list[{BaseGate, Circuit}]]:
"""
Split circuit in moments.
"""
from hybridq.gate import TupleGate
# Convert iterable to list
circuit = list(circuit)
# If circuit is empty, return a single empty TupleGate
if not circuit:
return [TupleGate()]
# Get qubits
def _get_qubits(x):
if isinstance(x, BaseGate):
return x.qubits if x.n_qubits else tuple()
elif isinstance(x, Circuit):
return x.all_qubits()
else:
raise ValueError(f"'{x}' is not valid.")
# Get all used qubits
qubits = sort({q for x in circuit for q in _get_qubits(x)})
# Get map of leves
level_map = {q: 0 for q in qubits}
level = [0] * len(circuit)
# Get the right level for each object ..
for i, x in enumerate(circuit):
# Get qubits
_qubits = _get_qubits(x)
# If gate is acting on qubits, add gate to the right level
if _qubits:
# Get max level
level[i] = np.max([level_map[q] for q in _get_qubits(x)]) + 1
# Update level_map
level_map.update({q: level[i] for q in _get_qubits(x)})
# .. otherwise, simply update all qubits to create a new moment
else:
level[i] = np.max(level) + 1
level_map = {q: level[i] for q in qubits}
# Initialize moments
moments = [[] for _ in range(np.max(level))]
# Update moments
for i, x in enumerate(circuit):
moments[level[i] - 1].append(x)
# Return moments
return list(map(TupleGate, moments))
def qubits(self) -> tuple[any, ...]:
from hybridq.utils import sort
# If empty, return empty tuple
if not len(self):
return tuple()
# Get all qubits
_qubits = tuple(g.qubits if g.provides('qubits') else None
for g in self)
# If any None is present, return None
if any(q is None for q in _qubits):
return None
# Flatten list and remove duplicates
else:
return tuple(sort(set(y for x in _qubits for y in x)))
def _simulate_tn_mpi(circuit: Circuit, initial_state: any, final_state: any,
optimize: any, backend: any, complex_type: any,
tensor_only: bool, verbose: bool, **kwargs):
import quimb.tensor as tn
import cotengra as ctg
# Get MPI
_mpi_comm = MPI.COMM_WORLD
_mpi_size = _mpi_comm.Get_size()
_mpi_rank = _mpi_comm.Get_rank()
# Set default parameters
kwargs.setdefault('compress', 2)
kwargs.setdefault('simplify_tn', 'RC')
kwargs.setdefault('max_iterations', 1)
kwargs.setdefault('methods', ['kahypar', 'greedy'])
kwargs.setdefault('max_time', 120)
kwargs.setdefault('max_repeats', 16)
kwargs.setdefault('minimize', 'combo')
kwargs.setdefault('target_largest_intermediate', 0)
kwargs.setdefault('max_largest_intermediate', 2**26)
kwargs.setdefault('temperatures', [1.0, 0.1, 0.01])
kwargs.setdefault('parallel', None)
kwargs.setdefault('cotengra', {})
kwargs.setdefault('max_n_slices', None)
kwargs.setdefault('return_info', False)
# Get random leaves_prefix
leaves_prefix = ''.join(
np.random.choice(list('abcdefghijklmnopqrstuvwxyz'), size=20))
# Initialize info
_sim_info = {}
# Alias for tn
if optimize == 'tn':
optimize = 'cotengra'
if isinstance(circuit, Circuit):
if not kwargs['parallel']:
kwargs['parallel'] = 1
else:
# If number of threads not provided, just use half of the number of available cpus
if isinstance(kwargs['parallel'],
bool) and kwargs['parallel'] == True:
kwargs['parallel'] = cpu_count() // 2
if optimize is not None and kwargs['parallel'] and kwargs[
'max_iterations'] == 1:
warn("Parallelization for MPI works for multiple iterations only. "
"For a better performance, use: 'max_iterations' > 1")
# Get number of qubits
qubits = circuit.all_qubits()
n_qubits = len(qubits)
# If initial/final state is None, set to all .'s
initial_state = '.' * n_qubits if initial_state is None else initial_state
final_state = '.' * n_qubits if final_state is None else final_state
# Initial and final states must be valid strings
for state, sname in [(initial_state, 'initial_state'),
(final_state, 'final_state')]:
# Get alphabet
from string import ascii_letters
# Check if string
if not isinstance(state, str):
raise ValueError(f"'{sname}' must be a valid string.")
# Deprecated error
if any(x in 'xX' for x in state):
from warnings import warn
# Define new DeprecationWarning (to always print the warning
# signal)
class DeprecationWarning(Warning):
pass
# Warn the user that '.' is used to represent open qubits
warn(
"Since '0.6.3', letters in the alphabet are used to "
"trace selected qubits (including 'x' and 'X'). "
"Instead, '.' is used to represent an open qubit.",
DeprecationWarning)
# Check only valid symbols are present
if set(state).difference('01+-.' + ascii_letters):
raise ValueError(f"'{sname}' contains invalid symbols.")
# Check number of qubits
if len(state) != n_qubits:
raise ValueError(f"'{sname}' has the wrong number of qubits "
f"(expected {n_qubits}, got {len(state)})")
# Check memory
if 2**(initial_state.count('.') +
final_state.count('.')) > kwargs['max_largest_intermediate']:
raise MemoryError("Memory for the given number of open qubits "
"exceeds the 'max_largest_intermediate'.")
# Compress circuit
if kwargs['compress']:
if verbose:
print(
f"Compress circuit (max_n_qubits={kwargs['compress']}): ",
end='',
file=stderr)
_time = time()
circuit = utils.compress(
circuit,
kwargs['compress']['max_n_qubits'] if isinstance(
kwargs['compress'], dict) else kwargs['compress'],
verbose=verbose,
**({
k: v
for k, v in kwargs['compress'].items()
if k != 'max_n_qubits'
} if isinstance(kwargs['compress'], dict) else {}))
circuit = Circuit(
utils.to_matrix_gate(c, complex_type=complex_type)
for c in circuit)
if verbose:
print(f"Done! ({time()-_time:1.2f}s)", file=stderr)
# Get tensor network representation of circuit
tensor, tn_qubits_map = utils.to_tn(circuit,
return_qubits_map=True,
leaves_prefix=leaves_prefix)
# Define basic MPS
_mps = {
'0': np.array([1, 0]),
'1': np.array([0, 1]),
'+': np.array([1, 1]) / np.sqrt(2),
'-': np.array([1, -1]) / np.sqrt(2)
}
# Attach initial/final state
for state, ext in [(initial_state, 'i'), (final_state, 'f')]:
for s, q in ((s, q) for s, q in zip(state, qubits) if s in _mps):
inds = [f'{leaves_prefix}_{tn_qubits_map[q]}_{ext}']
tensor &= tn.Tensor(_mps[s], inds=inds, tags=inds)
# For each unique letter, apply trace
for x in set(initial_state + final_state).difference(''.join(_mps) +
'.'):
# Get indexes
inds = [
f'{leaves_prefix}_{tn_qubits_map[q]}_i'
for s, q in zip(initial_state, qubits) if s == x
]
inds += [
f'{leaves_prefix}_{tn_qubits_map[q]}_f'
for s, q in zip(final_state, qubits) if s == x
]
# Apply trace
tensor &= tn.Tensor(np.reshape([1] + [0] * (2**len(inds) - 2) +
[1], (2, ) * len(inds)),
inds=inds)
# Simplify if requested
if kwargs['simplify_tn']:
tensor.full_simplify_(kwargs['simplify_tn']).astype_(complex_type)
else:
# Otherwise, just convert to the given complex_type
tensor.astype_(complex_type)
# Get contraction from heuristic
if optimize == 'cotengra' and kwargs['max_iterations'] > 0:
# Set cotengra parameters
def cotengra_params():
# Get HyperOptimizer
q = ctg.HyperOptimizer(methods=kwargs['methods'],
max_time=kwargs['max_time'],
max_repeats=kwargs['max_repeats'],
minimize=kwargs['minimize'],
progbar=False,
parallel=False,
**kwargs['cotengra'])
# For some optlib, HyperOptimizer._retrieve_params is not
# pickeable. Let's fix the problem by hand.
q._retrieve_params = __FunctionWrap(q._retrieve_params)
# Return HyperOptimizer
return q
# Get target size
tli = kwargs['target_largest_intermediate']
with Pool(kwargs['parallel']) as pool:
# Sumbit jobs
_opts = [
cotengra_params() for _ in range(kwargs['max_iterations'])
]
_map = [
pool.apply_async(tensor.contract, (all, ),
dict(optimize=_opt, get='path-info'))
for _opt in _opts
]
with tqdm(total=len(_map),
disable=not verbose,
desc='Collecting contractions') as pbar:
_old_completed = 0
while 1:
# Count number of completed
_completed = 0
for _w in _map:
_completed += _w.ready()
if _w.ready() and not _w.successful():
_w.get()
# Update pbar
pbar.update(_completed - _old_completed)
_old_completed = _completed
if _completed == len(_map):
break
# Wait
sleep(1)
# Collect results
_infos = [_w.get() for _w in _map]
if kwargs['minimize'] == 'size':
opt, info = sort(
zip(_opts, _infos),
key=lambda w:
(w[1].largest_intermediate, w[0].best['flops']))[0]
else:
opt, info = sort(
zip(_opts, _infos),
key=lambda w:
(w[0].best['flops'], w[1].largest_intermediate))[0]
if optimize == 'cotengra':
# Gather best contractions
_cost = _mpi_comm.gather(
(info.largest_intermediate, info.opt_cost, _mpi_rank), root=0)
if _mpi_rank == 0:
if kwargs['minimize'] == 'size':
_best_rank = sort(_cost, key=lambda x: (x[0], x[1]))[0][-1]
else:
_best_rank = sort(_cost, key=lambda x: (x[1], x[0]))[0][-1]
else:
_best_rank = None
_best_rank = _mpi_comm.bcast(_best_rank, root=0)
if hasattr(opt, '_pool'):
del (opt._pool)
# Distribute opt/info
tensor, info, opt = _mpi_comm.bcast((tensor, info, opt),
root=_best_rank)
# Just return tensor if required
if tensor_only:
if optimize == 'cotengra' and kwargs['max_iterations'] > 0:
return tensor, (info, opt)
else:
return tensor
else:
# Set tensor
tensor = circuit
if len(optimize) == 2 and isinstance(
optimize[0], PathInfo) and isinstance(
optimize[1], ctg.hyper.HyperOptimizer):
# Get info and opt from optimize
info, opt = optimize
# Set optimization
optimize = 'cotengra'
else:
# Get tensor and path
tensor = circuit
# Print some info
if verbose and _mpi_rank == 0:
print(
f'Largest Intermediate: 2^{np.log2(float(info.largest_intermediate)):1.2f}',
file=stderr)
print(
f'Max Largest Intermediate: 2^{np.log2(float(kwargs["max_largest_intermediate"])):1.2f}',
file=stderr)
print(f'Flops: 2^{np.log2(float(info.opt_cost)):1.2f}', file=stderr)
if optimize == 'cotengra':
if _mpi_rank == 0:
# Get indexes
_inds = tensor.outer_inds()
# Get input indexes and output indexes
_i_inds = sort([x for x in _inds if x[-2:] == '_i'],
key=lambda x: int(x.split('_')[1]))
_f_inds = sort([x for x in _inds if x[-2:] == '_f'],
key=lambda x: int(x.split('_')[1]))
# Get order
_inds = [_inds.index(x) for x in _i_inds + _f_inds]
# Get slice finder
sf = ctg.SliceFinder(
info,
target_size=kwargs['max_largest_intermediate'],
allow_outer=False)
# Find slices
with tqdm(kwargs['temperatures'], disable=not verbose,
leave=False) as pbar:
for _temp in pbar:
pbar.set_description(f'Find slices (T={_temp})')
ix_sl, cost_sl = sf.search(temperature=_temp)
# Get slice contractor
sc = sf.SlicedContractor([t.data for t in tensor])
# Make sure that no open qubits are sliced
assert (not {
ix: i
for i, ix in enumerate(sc.output) if ix in sc.sliced
})
# Print some infos
if verbose:
print(
f'Number of slices: 2^{np.log2(float(cost_sl.nslices)):1.2f}',
file=stderr)
print(
f'Flops+Cuts: 2^{np.log2(float(cost_sl.total_flops)):1.2f}',
file=stderr)
# Update infos
_sim_info.update({
'flops': info.opt_cost,
'largest_intermediate': info.largest_intermediate,
'n_slices': cost_sl.nslices,
'total_flops': cost_sl.total_flops
})
# Get slices
slices = list(range(cost_sl.nslices + 1)) + [None] * (
_mpi_size -
cost_sl.nslices) if cost_sl.nslices < _mpi_size else [
cost_sl.nslices / _mpi_size * i for i in range(_mpi_size)
] + [cost_sl.nslices]
if not np.alltrue(
[int(x) == x
for x in slices if x is not None]) or not np.alltrue([
slices[i] < slices[i + 1] for i in range(_mpi_size)
if slices[i] is not None and slices[i + 1] is not None
]):
raise RuntimeError('Something went wrong')
# Convert all to integers
slices = [int(x) if x is not None else None for x in slices]
else:
sc = slices = None
# Distribute slicer and slices
sc, slices = _mpi_comm.bcast((sc, slices), root=0)
_n_slices = max(x for x in slices if x)
if kwargs['max_n_slices'] and _n_slices > kwargs['max_n_slices']:
raise RuntimeError(
f'Too many slices ({_n_slices} > {kwargs["max_n_slices"]})')
# Contract slices
_tensor = None
if slices[_mpi_rank] is not None and slices[_mpi_rank + 1] is not None:
for i in tqdm(range(slices[_mpi_rank], slices[_mpi_rank + 1]),
desc='Contracting slices',
disable=not verbose,
leave=False):
if _tensor is None:
_tensor = np.copy(sc.contract_slice(i, backend=backend))
else:
_tensor += sc.contract_slice(i, backend=backend)
# Gather tensors
if _mpi_rank != 0:
_mpi_comm.send(_tensor, dest=0, tag=11)
elif _mpi_rank == 0:
for i in tqdm(range(1, _mpi_size),
desc='Collecting tensors',
disable=not verbose):
_p_tensor = _mpi_comm.recv(source=i, tag=11)
if _p_tensor is not None:
_tensor += _p_tensor
if _mpi_rank == 0:
# Create map
_map = ''.join([get_symbol(x) for x in range(len(_inds))])
_map += '->'
_map += ''.join([get_symbol(x) for x in _inds])
# Reorder tensor
tensor = contract(_map, _tensor)
# Deprecated
## Reshape tensor
#if _inds:
# if _i_inds and _f_inds:
# tensor = np.reshape(tensor,
# (2**len(_i_inds), 2**len(_f_inds)))
# else:
# tensor = np.reshape(tensor,
# (2**max(len(_i_inds), len(_f_inds)),))
else:
tensor = None
else:
if _mpi_rank == 0:
# Contract tensor
tensor = tensor.contract(optimize=optimize, backend=backend)
if hasattr(tensor, 'inds'):
# Get input indexes and output indexes
_i_inds = sort([x for x in tensor.inds if x[-2:] == '_i'],
key=lambda x: int(x.split('_')[1]))
_f_inds = sort([x for x in tensor.inds if x[-2:] == '_f'],
key=lambda x: int(x.split('_')[1]))
# Transpose tensor
tensor.transpose(*(_i_inds + _f_inds), inplace=True)
# Deprecated
## Reshape tensor
#if _i_inds and _f_inds:
# tensor = np.reshape(tensor,
# (2**len(_i_inds), 2**len(_f_inds)))
#else:
# tensor = np.reshape(tensor,
# (2**max(len(_i_inds), len(_f_inds)),))
else:
tensor = None
if kwargs['return_info']:
return tensor, _sim_info
else:
return tensor
def commutes_with(self, gate: PowerMatrixGate, atol: float = 1e-7) -> bool:
"""
Return `True` if the calling gate commutes with `gate`.
Parameters
----------
gate: PowerMatrixGate
Gate to check commutation with.
atol: float
Absolute tollerance.
Returns
-------
bool
`True` if the calling gate commutes with `gate`, otherwise `False`.
"""
from string import ascii_lowercase as alc, ascii_uppercase as auc
# Check both gates have qubits
if self.qubits is None or gate.qubits is None:
raise ValueError("Cannot check commutation between virtual gates.")
# Get shared qubits
shared_qubits = sort(set(self.qubits).intersection(gate.qubits))
# If no qubits are shared, the gates definitely commute
if not shared_qubits:
return True
# Rename
g1, g2 = self, gate
# Get all qubits
q12 = tuple(sort(set(g1.qubits + g2.qubits)))
# Get number of qubits
n12 = len(q12)
# Get unitaries
U1 = np.reshape(g1.matrix(), (2, ) * 2 * g1.n_qubits)
U2 = np.reshape(g2.matrix(), (2, ) * 2 * g2.n_qubits)
# Define how to multiply matrices
def _mul(w1, w2):
# Get qubits and unitaries
q1, U1 = w1
q2, U2 = w2
# Get number of qubits
n1 = len(q1)
n2 = len(q2)
# Construct map
_map = ''
_map += ''.join(alc[q12.index(q)] for q in q1)
_map += ''.join(auc[-shared_qubits.index(q) -
1 if q in shared_qubits else q12.index(q)]
for q in q1)
_map += ','
_map += ''.join(auc[-shared_qubits.index(q) -
1] if q in shared_qubits else alc[q12.index(q)]
for q in q2)
_map += ''.join(auc[q12.index(q)] for q in q2)
_map += '->'
_map += ''.join(alc[x] for x in range(n12))
_map += ''.join(auc[x] for x in range(n12))
# Multiply map
return np.einsum(_map, U1, U2)
# Compute products
P1 = _mul((g1.qubits, U1), (g2.qubits, U2))
P2 = _mul((g2.qubits, U2), (g1.qubits, U1))
# Check if the same
return np.allclose(P1, P2, atol=1e-5)
def matrix(self, order: iter[any] = None) -> np.ndarray:
"""
Return matrix representing `MatrixPowerGate`. If `order` is provided,
the given order of qubits is used to output its matrix.
Parameters
----------
order: iter[any]
Order of qubits used to output the matrix.
Returns
-------
array_like
Matrix representing `MatrixPowerGate`.
Example
-------
>>> g = PowerMatrixGate(qubits=[0, 1], U=[[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 0, 1], [0, 0, 1, 0]])
array([[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 0, 1],
[0, 0, 1, 0]])
The order of qubits is `[1, 0]`. On the contrary:
>>> g.on().matrix(order=[1, 0])
array([[1, 0, 0, 0],
[0, 0, 0, 1],
[0, 0, 1, 0],
[0, 1, 0, 0]])
outputs a matrix with the qubits order being if `[0, 1]`.
"""
# Get Unitary
_U = np.asarray(self.Matrix)
if order is not None:
# Covert order to list
order = list(order)
# Order is allowed only if gate.qubits are specified
if self.qubits is None or sort(order) != sort(self.qubits):
raise ValueError(
"'order' is not a permutation of 'gate.qubits'.")
# Reorder matrix in case qubits are out-of-order
if order and order != self.qubits:
# Transpose
_U = np.reshape(
np.transpose(
np.reshape(_U, (2, ) * (2 * self.n_qubits)),
[self.qubits.index(q) for q in order] +
[self.n_qubits + self.qubits.index(q) for q in order]),
(2**self.n_qubits, 2**self.n_qubits))
# Apply power
if self.power != 1:
_U = powm(_U, float(self.power))
# Apply conjugation
if self.__conj:
_U = _U.conj()
# Apply transposition
if self.__T:
_U = _U.T
# Return matrix
return _U
def _unique_flatten(l):
from hybridq.utils import sort
return sort(set(y for x in l for y in x))
def pad(gate: Gate,
qubits: iter[any],
order: iter[any] = None,
return_matrix_only: bool = False) -> {MatrixGate, np.ndarray}:
"""
Pad `gate` to act on `qubits`. More precisely, if `gate` is acting on a
subset of `qubits`, extend `gate` with identities to act on all `qubits`.
Parameters
----------
gate: Gate
The gate to pad.
qubits: iter[any]
Qubits used to pad `gate`. If `gate.qubits` is not a subset of
`qubits`, raise an error.
order: iter[any], optional
If provided, reorder qubits in the final gate accordingly to `qubits`.
return_matrix_only: bool, optional
If `True`, the matrix representing the state is returned instead of
`MatrixGate` (default: `False`).
Returns
-------
MatrixGate
The padded gate acting on `qubits`.
"""
from hybridq.gate import MatrixGate
from hybridq.utils import sort
# Convert qubits to tuple
qubits = tuple(qubits)
# Convert order to tuple if provided
order = None if order is None else tuple(order)
# Check that order is a permutation of qubits
if order and sort(qubits) != sort(order):
raise ValueError("'order' must be a permutation of 'qubits'")
# 'gate' must have qubits and it must be a subset of 'qubits'
if not gate.provides('qubits') or set(gate.qubits).difference(qubits):
raise ValueError("'gate' must provide qubits and those "
"qubits must be a subset of 'qubits'.")
# Get matrix
M = gate.matrix()
# Pad matrix with identity
if gate.n_qubits != len(qubits):
M = np.kron(M, np.eye(2**(len(qubits) - gate.n_qubits)))
# Get new qubits
qubits = gate.qubits + tuple(set(qubits).difference(gate.qubits))
# Reorder if required
if order and order != qubits:
# Get new matrix
M = MatrixGate(M, qubits=qubits).matrix(order=order)
# Set new qubits
qubits = order
# Return gate
return M if return_matrix_only else MatrixGate(
M, qubits=qubits, tags=gate.tags if gate.provides('tags') else {})
def _simulate_tn(circuit: any, initial_state: any, final_state: any,
optimize: any, backend: any, complex_type: any,
tensor_only: bool, verbose: bool, **kwargs):
import quimb.tensor as tn
import cotengra as ctg
# Get random leaves_prefix
leaves_prefix = ''.join(
np.random.choice(list('abcdefghijklmnopqrstuvwxyz'), size=20))
# Initialize info
_sim_info = {}
# Alias for tn
if optimize == 'tn':
optimize = 'cotengra'
if isinstance(circuit, Circuit):
# Get number of qubits
qubits = circuit.all_qubits()
n_qubits = len(qubits)
# If initial/final state is None, set to all .'s
initial_state = '.' * n_qubits if initial_state is None else initial_state
final_state = '.' * n_qubits if final_state is None else final_state
# Initial and final states must be valid strings
for state, sname in [(initial_state, 'initial_state'),
(final_state, 'final_state')]:
# Get alphabet
from string import ascii_letters
# Check if string
if not isinstance(state, str):
raise ValueError(f"'{sname}' must be a valid string.")
# Deprecated error
if any(x in 'xX' for x in state):
from hybridq.utils import DeprecationWarning
from warnings import warn
# Warn the user that '.' is used to represent open qubits
warn(
"Since '0.6.3', letters in the alphabet are used to "
"trace selected qubits (including 'x' and 'X'). "
"Instead, '.' is used to represent an open qubit.",
DeprecationWarning)
# Check only valid symbols are present
if set(state).difference('01+-.' + ascii_letters):
raise ValueError(f"'{sname}' contains invalid symbols.")
# Check number of qubits
if len(state) != n_qubits:
raise ValueError(f"'{sname}' has the wrong number of qubits "
f"(expected {n_qubits}, got {len(state)})")
# Check memory
if 2**(initial_state.count('.') +
final_state.count('.')) > kwargs['max_largest_intermediate']:
raise MemoryError("Memory for the given number of open qubits "
"exceeds the 'max_largest_intermediate'.")
# Compress circuit
if kwargs['compress']:
if verbose:
print(
f"Compress circuit (max_n_qubits={kwargs['compress']}): ",
end='',
file=stderr)
_time = time()
circuit = utils.compress(
circuit,
kwargs['compress']['max_n_qubits'] if isinstance(
kwargs['compress'], dict) else kwargs['compress'],
verbose=verbose,
**({
k: v
for k, v in kwargs['compress'].items()
if k != 'max_n_qubits'
} if isinstance(kwargs['compress'], dict) else {}))
circuit = Circuit(
utils.to_matrix_gate(c, complex_type=complex_type)
for c in circuit)
if verbose:
print(f"Done! ({time()-_time:1.2f}s)", file=stderr)
# Get tensor network representation of circuit
tensor, tn_qubits_map = utils.to_tn(circuit,
return_qubits_map=True,
leaves_prefix=leaves_prefix)
# Define basic MPS
_mps = {
'0': np.array([1, 0]),
'1': np.array([0, 1]),
'+': np.array([1, 1]) / np.sqrt(2),
'-': np.array([1, -1]) / np.sqrt(2)
}
# Attach initial/final state
for state, ext in [(initial_state, 'i'), (final_state, 'f')]:
for s, q in ((s, q) for s, q in zip(state, qubits) if s in _mps):
inds = [f'{leaves_prefix}_{tn_qubits_map[q]}_{ext}']
tensor &= tn.Tensor(_mps[s], inds=inds, tags=inds)
# For each unique letter, apply trace
for x in set(initial_state + final_state).difference(''.join(_mps) +
'.'):
# Get indexes
inds = [
f'{leaves_prefix}_{tn_qubits_map[q]}_i'
for s, q in zip(initial_state, qubits) if s == x
]
inds += [
f'{leaves_prefix}_{tn_qubits_map[q]}_f'
for s, q in zip(final_state, qubits) if s == x
]
# Apply trace
tensor &= tn.Tensor(np.reshape([1] + [0] * (2**len(inds) - 2) +
[1], (2, ) * len(inds)),
inds=inds)
# Simplify if requested
if kwargs['simplify_tn']:
tensor.full_simplify_(kwargs['simplify_tn']).astype_(complex_type)
else:
# Otherwise, just convert to the given complex_type
tensor.astype_(complex_type)
# Get contraction from heuristic
if optimize == 'cotengra' and kwargs['max_iterations'] > 0:
# Create local client if MPI has been detected (not compatible with Dask at the moment)
if _mpi_env and kwargs['parallel']:
from distributed import Client, LocalCluster
_client = Client(LocalCluster(processes=False))
else:
_client = None
# Set cotengra parameters
cotengra_params = lambda: ctg.HyperOptimizer(
methods=kwargs['methods'],
max_time=kwargs['max_time'],
max_repeats=kwargs['max_repeats'],
minimize=kwargs['minimize'],
progbar=verbose,
parallel=kwargs['parallel'],
**kwargs['cotengra'])
# Get optimized path
opt = cotengra_params()
info = tensor.contract(all, optimize=opt, get='path-info')
# Get target size
tli = kwargs['target_largest_intermediate']
# Repeat for the requested number of iterations
for _ in range(1, kwargs['max_iterations']):
# Break if largest intermediate is equal or smaller than target
if info.largest_intermediate <= tli:
break
# Otherwise, restart
_opt = cotengra_params()
_info = tensor.contract(all, optimize=_opt, get='path-info')
# Store the best
if kwargs['minimize'] == 'size':
if _info.largest_intermediate < info.largest_intermediate or (
_info.largest_intermediate
== info.largest_intermediate
and _opt.best['flops'] < opt.best['flops']):
info = _info
opt = _opt
else:
if _opt.best['flops'] < opt.best['flops'] or (
_opt.best['flops'] == opt.best['flops']
and _info.largest_intermediate <
info.largest_intermediate):
info = _info
opt = _opt
# Close client if exists
if _client:
_client.shutdown()
_client.close()
# Just return tensor if required
if tensor_only:
if optimize == 'cotengra' and kwargs['max_iterations'] > 0:
return tensor, (info, opt)
else:
return tensor
else:
# Set tensor
tensor = circuit
if len(optimize) == 2 and isinstance(
optimize[0], PathInfo) and isinstance(
optimize[1], ctg.hyper.HyperOptimizer):
# Get info and opt from optimize
info, opt = optimize
# Set optimization
optimize = 'cotengra'
else:
# Get tensor and path
tensor = circuit
# Print some info
if verbose:
print(
f'Largest Intermediate: 2^{np.log2(float(info.largest_intermediate)):1.2f}',
file=stderr)
print(
f'Max Largest Intermediate: 2^{np.log2(float(kwargs["max_largest_intermediate"])):1.2f}',
file=stderr)
print(f'Flops: 2^{np.log2(float(info.opt_cost)):1.2f}', file=stderr)
if optimize == 'cotengra':
# Get indexes
_inds = tensor.outer_inds()
# Get input indexes and output indexes
_i_inds = sort([x for x in _inds if x[-2:] == '_i'],
key=lambda x: int(x.split('_')[1]))
_f_inds = sort([x for x in _inds if x[-2:] == '_f'],
key=lambda x: int(x.split('_')[1]))
# Get order
_inds = [_inds.index(x) for x in _i_inds + _f_inds]
# Get slice finder
sf = ctg.SliceFinder(info,
target_size=kwargs['max_largest_intermediate'])
# Find slices
with tqdm(kwargs['temperatures'], disable=not verbose,
leave=False) as pbar:
for _temp in pbar:
pbar.set_description(f'Find slices (T={_temp})')
ix_sl, cost_sl = sf.search(temperature=_temp)
# Get slice contractor
sc = sf.SlicedContractor([t.data for t in tensor])
# Update infos
_sim_info.update({
'flops': info.opt_cost,
'largest_intermediate': info.largest_intermediate,
'n_slices': cost_sl.nslices,
'total_flops': cost_sl.total_flops
})
# Print some infos
if verbose:
print(
f'Number of slices: 2^{np.log2(float(cost_sl.nslices)):1.2f}',
file=stderr)
print(f'Flops+Cuts: 2^{np.log2(float(cost_sl.total_flops)):1.2f}',
file=stderr)
if kwargs['max_n_slices'] and sc.nslices > kwargs['max_n_slices']:
raise RuntimeError(
f'Too many slices ({sc.nslices} > {kwargs["max_n_slices"]})')
# Contract tensor
_li = np.log2(float(info.largest_intermediate))
_mli = np.log2(float(kwargs["max_largest_intermediate"]))
_tensor = sc.gather_slices((sc.contract_slice(
i, backend=backend
) for i in tqdm(
range(sc.nslices),
desc=f'Contracting tensor (li=2^{_li:1.0f}, mli=2^{_mli:1.1f})',
leave=False)))
# Create map
_map = ''.join([get_symbol(x) for x in range(len(_inds))])
_map += '->'
_map += ''.join([get_symbol(x) for x in _inds])
# Reorder tensor
tensor = contract(_map, _tensor)
# Deprecated
## Reshape tensor
#if _inds:
# if _i_inds and _f_inds:
# tensor = np.reshape(tensor, (2**len(_i_inds), 2**len(_f_inds)))
# else:
# tensor = np.reshape(tensor,
# (2**max(len(_i_inds), len(_f_inds)),))
else:
# Contract tensor
tensor = tensor.contract(optimize=optimize, backend=backend)
if hasattr(tensor, 'inds'):
# Get input indexes and output indexes
_i_inds = sort([x for x in tensor.inds if x[-2:] == '_i'],
key=lambda x: int(x.split('_')[1]))
_f_inds = sort([x for x in tensor.inds if x[-2:] == '_f'],
key=lambda x: int(x.split('_')[1]))
# Transpose tensor
tensor.transpose(*(_i_inds + _f_inds), inplace=True)
# Deprecated
## Reshape tensor
#if _i_inds and _f_inds:
# tensor = np.reshape(tensor, (2**len(_i_inds), 2**len(_f_inds)))
#else:
# tensor = np.reshape(tensor,
# (2**max(len(_i_inds), len(_f_inds)),))
if kwargs['return_info']:
return tensor, _sim_info
else:
return tensor
def _simulate_evolution(circuit: iter[Gate], initial_state: any,
final_state: any, optimize: any, backend: any,
complex_type: any, verbose: bool, **kwargs):
"""
Perform simulation of the circuit by using the direct evolution of the quantum state.
"""
if _detect_mpi:
warn("Detected MPI but optimize='evolution' does not support MPI.")
# Initialize info
_sim_info = {}
# Convert iterable to circuit
circuit = Circuit(circuit)
# Get number of qubits
qubits = circuit.all_qubits()
n_qubits = len(qubits)
# Check if core libraries have been loaded properly
if any(not x for x in
[_swap_core, _dot_core, _to_complex_core, _log2_pack_size]):
warn("Cannot find C++ HybridQ core. "
"Falling back to optimize='evolution-einsum' instead.")
optimize = 'einsum'
# If the system is too small, fallback to einsum
if optimize == 'hybridq' and n_qubits <= max(10, _log2_pack_size):
warn("The system is too small to use optimize='evolution-hybridq'. "
"Falling back to optimize='evolution-einsum'")
optimize = 'einsum'
if verbose:
print(f'# Optimization: {optimize}', file=stderr)
# Check memory
if 2**n_qubits > kwargs['max_largest_intermediate']:
raise MemoryError(
"Memory for the given number of qubits exceeds the 'max_largest_intermediate'."
)
# If final_state is specified, warn user
if final_state is not None:
warn(
f"'final_state' cannot be specified in optimize='{optimize}'. Ignoring 'final_state'."
)
# Initial state must be provided
if initial_state is None:
raise ValueError(
"'initial_state' must be specified for optimize='evolution'.")
# Convert complex_type to np.dtype
complex_type = np.dtype(complex_type)
# Print info
if verbose:
print(f"Compress circuit (max_n_qubits={kwargs['compress']}): ",
end='',
file=stderr)
_time = time()
# Compress circuit
circuit = utils.compress(
circuit,
kwargs['compress']['max_n_qubits'] if isinstance(
kwargs['compress'], dict) else kwargs['compress'],
verbose=verbose,
skip_compression=[pr.FunctionalGate],
**({
k: v
for k, v in kwargs['compress'].items() if k != 'max_n_qubits'
} if isinstance(kwargs['compress'], dict) else {}))
# Check that FunctionalGate's are not compressed
assert (all(not isinstance(g, pr.FunctionalGate) if len(x) > 1 else True
for x in circuit for g in x))
# Compress everything which is not a FunctionalGate
circuit = Circuit(g for c in (c if any(
isinstance(g, pr.FunctionalGate)
for g in c) else [utils.to_matrix_gate(c, complex_type=complex_type)]
for c in circuit) for g in c)
# Get state
initial_state = prepare_state(initial_state,
complex_type=complex_type) if isinstance(
initial_state, str) else initial_state
if verbose:
print(f"Done! ({time()-_time:1.2f}s)", file=stderr)
if optimize == 'hybridq':
if complex_type not in ['complex64', 'complex128']:
warn(
"optimize=evolution-hybridq only support ['complex64', 'complex128']. Using 'complex64'."
)
complex_type = np.dtype('complex64')
# Get float_type
float_type = np.real(np.array(1, dtype=complex_type)).dtype
# Get C float_type
c_float_type = {
np.dtype('float32'): ctypes.c_float,
np.dtype('float64'): ctypes.c_double
}[float_type]
# Load libraries
_apply_U = _dot_core[float_type]
# Get swap core
_swap = _swap_core[float_type]
# Get to_complex core
_to_complex = _to_complex_core[complex_type]
# Get states
_psi = aligned.empty(shape=(2, ) + initial_state.shape,
dtype=float_type,
order='C',
alignment=32)
# Split in real and imaginary part
_psi_re = _psi[0]
_psi_im = _psi[1]
# Check alignment
assert (_psi_re.ctypes.data % 32 == 0)
assert (_psi_im.ctypes.data % 32 == 0)
# Get C-pointers
_psi_re_ptr = _psi_re.ctypes.data_as(ctypes.POINTER(c_float_type))
_psi_im_ptr = _psi_im.ctypes.data_as(ctypes.POINTER(c_float_type))
# Initialize
np.copyto(_psi_re, np.real(initial_state))
np.copyto(_psi_im, np.imag(initial_state))
# Create index maps
_map = {q: n_qubits - x - 1 for x, q in enumerate(qubits)}
_inv_map = [q for q, _ in sort(_map.items(), key=lambda x: x[1])]
# Set largest swap_size
_max_swap_size = 0
# Start clock
_ini_time = time()
# Apply all gates
for gate in tqdm(circuit, disable=not verbose):
# FunctionalGate
if isinstance(gate, pr.FunctionalGate):
# Get order
order = tuple(
q
for q, _ in sorted(_map.items(), key=lambda x: x[1])[::-1])
# Apply gate to state
new_psi, new_order = gate.apply(psi=_psi, order=order)
# Copy back if needed
if new_psi is not _psi:
# Align if needed
_psi = aligned.asarray(new_psi,
order='C',
alignment=32,
dtype=_psi.dtype)
# Redefine real and imaginary part
_psi_re = _psi[0]
_psi_im = _psi[1]
# Get C-pointers
_psi_re_ptr = _psi_re.ctypes.data_as(
ctypes.POINTER(c_float_type))
_psi_im_ptr = _psi_im.ctypes.data_as(
ctypes.POINTER(c_float_type))
# This can be eventually fixed ...
if any(x != y for x, y in zip(order, new_order)):
raise RuntimeError("'order' has changed.")
elif gate.provides(['qubits', 'matrix']):
# Check if any qubits is withing the pack_size
if any(q in _inv_map[:_log2_pack_size] for q in gate.qubits):
#@@@ Alternative way to always use the smallest swap size
#@@@
#@@@ # Get positions
#@@@ _pos = np.fromiter((_map[q] for q in gate.qubits),
#@@@ dtype=int)
#@@@ # Get smallest swap size
#@@@ _swap_size = 0 if np.all(_pos >= _log2_pack_size) else next(
#@@@ k
#@@@ for k in range(_log2_pack_size, 2 *
#@@@ max(len(_pos), _log2_pack_size) + 1)
#@@@ if sum(_pos < k) <= k - _log2_pack_size)
#@@@ # Get new order
#@@@ _order = [
#@@@ x for x, q in enumerate(_inv_map[:_swap_size])
#@@@ if q not in gate.qubits
#@@@ ]
#@@@ _order += [
#@@@ x for x, q in enumerate(_inv_map[:_swap_size])
#@@@ if q in gate.qubits
#@@@ ]
if len(gate.qubits) <= 4:
# Get new order
_order = [
x for x, q in enumerate(_inv_map[:8])
if q not in gate.qubits
]
_order += [
x for x, q in enumerate(_inv_map[:8])
if q in gate.qubits
]
else:
# Get qubit indexes for gate
_gate_idxs = [_inv_map.index(q) for q in gate.qubits]
# Get new order
_order = [
x for x in range(n_qubits) if x not in _gate_idxs
][:_log2_pack_size]
_order += [x for x in _gate_idxs if x < max(_order)]
# Get swap size
_swap_size = len(_order)
# Update max swap size
if _swap_size > _max_swap_size:
_max_swap_size = _swap_size
# Update maps
_inv_map[:_swap_size] = [
_inv_map[:_swap_size][x] for x in _order
]
_map.update(
{q: x
for x, q in enumerate(_inv_map[:_swap_size])})
# Apply swap
_order = np.array(_order, dtype='uint32')
_swap(
_psi_re_ptr,
_order.ctypes.data_as(ctypes.POINTER(ctypes.c_uint32)),
n_qubits, len(_order))
_swap(
_psi_im_ptr,
_order.ctypes.data_as(ctypes.POINTER(ctypes.c_uint32)),
n_qubits, len(_order))
# Get positions
_pos = np.array([_map[q] for q in reversed(gate.qubits)],
dtype='uint32')
# Get matrix
_U = np.asarray(gate.matrix(), dtype=complex_type, order='C')
# Apply matrix
if _apply_U(
_psi_re_ptr, _psi_im_ptr,
_U.ctypes.data_as(ctypes.POINTER(c_float_type)),
_pos.ctypes.data_as(ctypes.POINTER(ctypes.c_uint32)),
n_qubits, len(_pos)):
raise RuntimeError('something went wrong')
else:
raise RuntimeError(f"'{gate}' not supported")
# Check maps are still consistent
assert (all(_inv_map[_map[q]] == q for q in _map))
# Swap back to the correct order
_order = np.array([_inv_map.index(q)
for q in reversed(qubits)][:_max_swap_size],
dtype='uint32')
_swap(_psi_re_ptr,
_order.ctypes.data_as(ctypes.POINTER(ctypes.c_uint32)), n_qubits,
len(_order))
_swap(_psi_im_ptr,
_order.ctypes.data_as(ctypes.POINTER(ctypes.c_uint32)), n_qubits,
len(_order))
# Stop clock
_end_time = time()
# Copy the results
if kwargs['return_numpy_array']:
_complex_psi = np.empty(_psi.shape[1:], dtype=complex_type)
_to_complex(
_psi_re_ptr, _psi_im_ptr,
_complex_psi.ctypes.data_as(ctypes.POINTER(c_float_type)),
2**n_qubits)
_psi = _complex_psi
# Update info
_sim_info['runtime (s)'] = _end_time - _ini_time
elif optimize.split('-')[0] == 'einsum':
optimize = '-'.join(optimize.split('-')[1:])
if not optimize:
optimize = 'auto'
# Split circuits to separate FunctionalGate's
circuit = utils.compress(
circuit,
max_n_qubits=len(qubits),
skip_compression=[pr.FunctionalGate],
**({
k: v
for k, v in kwargs['compress'].items() if k != 'max_n_qubits'
} if isinstance(kwargs['compress'], dict) else {}))
# Check that FunctionalGate's are not compressed
assert (all(
not isinstance(g, pr.FunctionalGate) if len(x) > 1 else True
for x in circuit for g in x))
# Prepare initial_state
_psi = initial_state
# Initialize time
_ini_time = time()
for circuit in circuit:
# Check
assert (all(not isinstance(g, pr.FunctionalGate) for g in circuit)
or len(circuit) == 1)
# Apply gate if functional
if len(circuit) == 1 and isinstance(circuit[0], pr.FunctionalGate):
# Apply gate to state
_psi, qubits = circuit[0].apply(psi=_psi, order=qubits)
else:
# Get gates and corresponding qubits
_qubits, _gates = zip(
*((c.qubits,
np.reshape(c.matrix().astype(complex_type), (2, ) *
(2 * len(c.qubits)))) for c in circuit))
# Initialize map
_map = {q: get_symbol(x) for x, q in enumerate(qubits)}
_count = n_qubits
_path = ''.join((_map[q] for q in qubits))
# Generate map
for _qs in _qubits:
# Initialize local paths
_path_in = _path_out = ''
# Add incoming legs
for _q in _qs:
_path_in += _map[_q]
# Add outcoming legs
for _q in _qs:
_map[_q] = get_symbol(_count)
_count += 1
_path_out += _map[_q]
# Update path
_path = _path_out + _path_in + ',' + _path
# Make sure that qubits order is preserved
_path += '->' + ''.join([_map[q] for q in qubits])
# Contracts
_psi = contract(_path,
*reversed(_gates),
_psi,
backend=backend,
optimize=optimize)
# Block JAX until result is ready (for a more precise runtime)
if backend == 'jax' and kwargs['block_until_ready']:
_psi.block_until_ready()
# Stop time
_end_time = time()
# Update info
_sim_info['runtime (s)'] = _end_time - _ini_time
else:
raise ValueError(f"optimize='{optimize}' not implemented.")
if verbose:
print(f'# Runtime (s): {_sim_info["runtime (s)"]:1.2f}', file=stderr)
# Return state
if kwargs['return_info']:
return _psi, _sim_info
else:
return _psi
def to_nx(circuit: iter[BaseGate],
add_final_nodes: bool = True,
node_tags: dict = None,
edge_tags: dict = None,
return_qubits_map: bool = False,
leaves_prefix: str = 'q') -> networkx.Graph:
"""
Return graph representation of circuit. `to_nx` is deterministic, so it can
be reused elsewhere.
Parameters
----------
circuit: iter[BaseGate]
Circuit to get graph representation from.
add_final_nodes: bool, optional
Add final nodes for each qubit to the graph representation of `circuit`.
node_tags: dict, optional
Add specific tags to nodes.
edge_tags: dict, optional
Add specific tags to edges.
return_qubits_map: bool, optional
Return map associated to the Circuit qubits.
leaves_prefix: str, optional
Specify prefix to use for leaves.
Returns
-------
networkx.Graph
Graph representing `circuit`.
Example
-------
>>> import networkx as nx
>>>
>>> # Define circuit
>>> circuit = Circuit(
>>> [Gate('X', qubits=[0])**1.2,
>>> Gate('ISWAP', qubits=[0, 1])**2.3], Gate('H', [1]))
>>>
>>> # Draw graph
>>> nx.draw_planar(utils.to_nx(circuit))
.. image:: ../../images/circuit_nx.png
"""
import networkx as nx
# Initialize
if node_tags is None:
node_tags = {}
if edge_tags is None:
edge_tags = {}
# Check if node is a leaf
def _is_leaf(node):
return type(node) == str and node[:len(leaves_prefix)] == leaves_prefix
# Convert iterable to Circuit
circuit = Circuit(circuit)
# Get graph
graph = nx.DiGraph()
# Get qubits
qubits = circuit.all_qubits()
# Get qubits_map
qubits_map = {q: i for i, q in enumerate(qubits)}
# Check that no qubits is 'confused' as leaf
if any(_is_leaf(q) for q in qubits):
raise ValueError(
f"No qubits must start with 'leaves_prefix'={leaves_prefix}.")
# Add first layer
for q in qubits:
graph.add_node(f'{leaves_prefix}_{qubits_map[q]}_i',
qubits=[q],
**node_tags)
# Last leg
last_leg = {q: f'{leaves_prefix}_{qubits_map[q]}_i' for q in qubits}
# Build network
for x, gate in enumerate(circuit):
# Add node
graph.add_node(x,
circuit=Circuit([gate]),
qubits=sort(gate.qubits),
**node_tags)
# Add edges (time directed)
graph.add_edges_from([(last_leg[q], x) for q in gate.qubits],
**edge_tags)
# Update last_leg
last_leg.update({q: x for q in gate.qubits})
# Add last indexes if required
if add_final_nodes:
for q in qubits:
graph.add_node(f'{leaves_prefix}_{qubits_map[q]}_f',
qubits=[q],
**node_tags)
graph.add_edges_from([(x, f'{leaves_prefix}_{qubits_map[q]}_f')
for q, x in last_leg.items()], **edge_tags)
if return_qubits_map:
return graph, qubits_map
else:
return graph
def generate_OTOC(layout: dict[any, list[Coupling]],
depth: int,
sequence: list[any],
one_qb_gates: iter[Gate],
two_qb_gates: iter[Gate],
butterfly_op: str,
ancilla: Qubit,
targets: list[Qubit],
qubits_order: list[Qubit] = None) -> Circuit:
# Get all qubits
all_qubits = {
q
for s in sequence[:min(depth, len(sequence))] for gate in layout[s]
for q in gate
}
# Get order of qubits
qubits_order = sort(all_qubits) if qubits_order is None else qubits_order
# Get list if single butterfly is provided
butterfly_op = list(butterfly_op)
# Check order of qubits
if sort(all_qubits) != sort(qubits_order):
raise ValueError(
"'qubits_order' must be a valid permutation of all qubits.")
# Check if butterfly op has valid strings
if set(butterfly_op).difference(['I', 'X', 'Y', 'Z']):
raise ValueError('Only {I, X, Y, Z} are valid butterfly operators')
# Check if ancilla/targets are in layout
if set(targets).union([ancilla]).difference(all_qubits):
raise ValueError(f"Ancilla/Targets must be in layout.")
# Check if targets are unique
if len(set(targets)) != len(targets):
raise ValueError('Targets must be unique.')
# Check that ancilla is not in targets
if ancilla in targets:
raise ValueError('Ancilla must be different from targets')
# Check if the number of targets corresponds to the number of butterfly ops
if len(targets) != len(butterfly_op) + 1:
raise ValueError(
f"Number of butterfly operators does not match number "
f"of targets (expected {len(targets)-1}, got {len(butterfly_op)})."
)
# Check that there is a coupling between the ancilla qubit and the measurement qubit
if next((False for s in sequence[:min(depth, len(sequence))]
for w in layout[s] if sort(w) == sort([ancilla, targets[0]])),
True):
raise ValueError(
f"No available two-qubit gate between ancilla {ancilla} "
f"and qubit {targets[0]}.")
# Initialize Circuit
circ = Circuit()
# Add initial layer of single qubit gates
circ.extend([
Gate('SQRT_Y' if q != ancilla else 'SQRT_X',
qubits=[q],
tags={
'depth': 0,
'sequence': 'initial'
}) for q in sort(all_qubits)
])
# Add CZ between ancilla and first target qubit
circ.append(
Gate('CZ', [ancilla, targets[0]],
tags={
'depth': 0,
'sequence': 'first_control'
}))
# Generate U
U = generate_U(layout=layout,
qubits_order=qubits_order,
depth=depth,
sequence=sequence,
one_qb_gates=one_qb_gates,
two_qb_gates=two_qb_gates,
exclude_qubits=[ancilla]).update_all_tags({'U': True})
# Add U to circuit
circ += U
# Add butterfly operator
circ.extend([
Gate(_b,
qubits=[_t],
tags={
'depth': depth - 1,
'sequence': 'butterfly'
}) for _b, _t in zip(butterfly_op, targets[1:])
])
# Add U* to circuit and update depth
circ += Circuit(
gate.update_tags({
'depth': 2 * depth - gate.tags['depth'] - 1,
'U^-1': True
}) for gate in U.inv().remove_all_tags(['U']))
# Add CZ between ancilla and first target qubit
circ.append(
Gate('CZ', [ancilla, targets[0]],
tags={
'depth': 2 * depth - 1,
'sequence': 'second_control'
}))
return circ
def map(self, order: iter[any] = None):
"""
Return map.
Parameters
----------
order: tuple[any, ...], optional
If provided, Kraus' map is ordered accordingly to `order`.
"""
# Get left and right qubits
l_qubits, r_qubits = self.qubits
# Get order
if order is not None:
from hybridq.utils import sort
# Get order
order = tuple(order)
try:
# Split
l_order, r_order = order
# Convert to tuples
l_order = tuple(l_order)
r_order = tuple(r_order)
# Check that qubits are consistent
if sort(l_order) != sort(l_qubits) or sort(r_order) != sort(
r_qubits):
raise RuntimeError("Something went wrong.")
# Get order
order = (l_order, r_order)
except:
if l_qubits != r_qubits or sort(order) != sort(l_qubits):
raise ValueError(
"'order' is not a valid permutation of qubits.")
# Get order
order = (order, order)
# Get Matrix representing the map
_U = self.Matrix
# Transpose if order is provided
if order is not None and (order[0] != self.l_qubits
or order[1] != self.r_qubits):
from hybridq.gate import MatrixGate
# Get gate
_g = MatrixGate(_U,
qubits=tuple((0, q) for q in l_qubits) + tuple(
(1, q) for q in r_qubits),
copy=False)
# Transpose
_U = _g.matrix(order=tuple((0, q) for q in order[0]) + tuple(
(1, q) for q in order[1]))
# Return map
return _U
def _get_state(state, name):
# If None, return None
if state is None:
return None
# Check if string
elif isinstance(state, str):
# If single char, extend to full size
state = state * (nl + nr) if len(state) == 1 else state
# Check that state has the right number of chars
if not (len(state) == (nl + nr) or
(l_qubits == r_qubits and len(state) == nl)):
raise ValueError(
f"'{name}' has the wrong number of qubits.")
# Extend if needed
state = state + state if len(state) == nl else state
# Return
return state
# Check if Circuit
elif isinstance(state, Circuit):
from hybridq.circuit.utils import matrix
# Check that qubits are consistent
if l_qubits != r_qubits or sort(l_qubits) != sort(
state.all_qubits()):
raise ValueError(
f"Qubits in '{name}' are not consistent with 'circuit'."
)
# Get matrix
U = matrix(state, order=l_qubits)
# Swap input/output
return np.transpose(np.reshape(U, (2, ) * 2 * nl),
list(range(nl, 2 * nl)) + list(range(nl)))
else:
# Try to convert to numpy array
state = np.asarray(state)
# At the moment, only 2-dimensional qubits are allowed
if set(state.shape) != {2}:
raise NotImplementedError(
"Only 2-dimensional qubits are allowed.")
# Check if the number of dimensions matches
if not (state.ndim == (nl + nr) or
(l_qubits == r_qubits and state.ndim == nl)):
raise ValueError(
f"'{name}' has the wrong number of qubits.")
# Extend if needed
if state.ndim == nl:
state = np.reshape(np.kron(state.ravel(), state.ravel()),
(2, ) * 2 * nl)
# Return state
return state