def mapping(self, map_type, threshold=0.00000001):
"""Map fermionic operator to qubit operator.
Using multiprocess to speedup the mapping, the improvement can be
observed when h2 is a non-sparse matrix.
Args:
map_type (str): case-insensitive mapping type.
"jordan_wigner", "parity", "bravyi_kitaev", "bksf"
threshold (float): threshold for Pauli simplification
Returns:
Operator: create an Operator object in Paulis form.
Raises:
QiskitChemistryError: if the `map_type` can not be recognized.
"""
"""
####################################################################
############ DEFINING MAPPED FERMIONIC OPERATORS ##############
####################################################################
"""
self._map_type = map_type
n = self._modes # number of fermionic modes / qubits
map_type = map_type.lower()
if map_type == 'jordan_wigner':
a = self._jordan_wigner_mode(n)
elif map_type == 'parity':
a = self._parity_mode(n)
elif map_type == 'bravyi_kitaev':
a = self._bravyi_kitaev_mode(n)
elif map_type == 'bksf':
return bksf_mapping(self)
else:
raise QiskitChemistryError(
'Please specify the supported modes: '
'jordan_wigner, parity, bravyi_kitaev, bksf')
"""
####################################################################
############ BUILDING THE MAPPED HAMILTONIAN ################
####################################################################
"""
pauli_list = Operator(paulis=[])
if logger.isEnabledFor(logging.DEBUG):
logger.debug("Mapping one-body terms to Qubit Hamiltonian:")
TextProgressBar(output_handler=sys.stderr)
results = parallel_map(
FermionicOperator._one_body_mapping,
[(self._h1[i, j], a[i], a[j])
for i, j in itertools.product(range(n), repeat=2)
if self._h1[i, j] != 0],
task_args=(threshold, ),
num_processes=aqua_globals.num_processes)
for result in results:
pauli_list += result
pauli_list.chop(threshold=threshold)
if logger.isEnabledFor(logging.DEBUG):
logger.debug("Mapping two-body terms to Qubit Hamiltonian:")
TextProgressBar(output_handler=sys.stderr)
results = parallel_map(
FermionicOperator._two_body_mapping,
[(self._h2[i, j, k, m], a[i], a[j], a[k], a[m])
for i, j, k, m in itertools.product(range(n), repeat=4)
if self._h2[i, j, k, m] != 0],
task_args=(threshold, ),
num_processes=aqua_globals.num_processes)
for result in results:
pauli_list += result
pauli_list.chop(threshold=threshold)
if self._ph_trans_shift is not None:
pauli_term = [
self._ph_trans_shift,
Pauli.from_label('I' * self._modes)
]
pauli_list += Operator(paulis=[pauli_term])
return pauli_list
def mapping(self, map_type, threshold=0.00000001, num_workers=4):
"""Map fermionic operator to qubit operator.
Using multiprocess to speedup the mapping, the improvement can be
observed when h2 is a non-sparse matrix.
Args:
map_type (str): case-insensitive mapping type.
"jordan_wigner", "parity", "bravyi_kitaev", "bksf"
threshold (float): threshold for Pauli simplification
num_workers (int): number of processes used to map.
Returns:
Operator: create an Operator object in Paulis form.
Raises:
QiskitChemistryError: if the `map_type` can not be recognized.
"""
"""
####################################################################
############ DEFINING MAPPED FERMIONIC OPERATORS ##############
####################################################################
"""
self._map_type = map_type
n = self._modes # number of fermionic modes / qubits
map_type = map_type.lower()
if map_type == 'jordan_wigner':
a = self._jordan_wigner_mode(n)
elif map_type == 'parity':
a = self._parity_mode(n)
elif map_type == 'bravyi_kitaev':
a = self._bravyi_kitaev_mode(n)
elif map_type == 'bksf':
return bksf_mapping(self)
else:
raise QiskitChemistryError(
'Please specify the supported modes: '
'jordan_wigner, parity, bravyi_kitaev, bksf')
"""
####################################################################
############ BUILDING THE MAPPED HAMILTONIAN ################
####################################################################
"""
max_workers = min(num_workers, multiprocessing.cpu_count())
pauli_list = Operator(paulis=[])
with concurrent.futures.ProcessPoolExecutor(
max_workers=max_workers) as executor:
# One-body
futures = [
executor.submit(FermionicOperator._one_body_mapping,
self._h1[i, j], a[i], a[j], threshold)
for i, j in itertools.product(range(n), repeat=2)
if self._h1[i, j] != 0
]
for future in futures:
result = future.result()
pauli_list += result
pauli_list.chop(threshold=threshold)
# Two-body
futures = [
executor.submit(FermionicOperator._two_body_mapping,
self._h2[i, j, k,
m], a[i], a[j], a[k], a[m], threshold)
for i, j, k, m in itertools.product(range(n), repeat=4)
if self._h2[i, j, k, m] != 0
]
for future in futures:
result = future.result()
pauli_list += result
pauli_list.chop(threshold=threshold)
if self._ph_trans_shift is not None:
pauli_term = [
self._ph_trans_shift,
Pauli.from_label('I' * self._modes)
]
pauli_list += Operator(paulis=[pauli_term])
return pauli_list