def begin_circuit(self,
num_subsystems,
cutoff_dim=None,
hbar=2,
pure=True,
**kwargs):
r"""
Create a quantum circuit (initialized in vacuum state) with the number of modes
equal to num_subsystems and a Fock-space cutoff dimension of cutoff_dim.
Args:
num_subsystems (int): number of modes the circuit should begin with
cutoff_dim (int): numerical cutoff dimension in Fock space for each mode.
``cutoff_dim=D`` represents the Fock states :math:`|0\rangle,\dots,|D-1\rangle`.
This argument is **required** for the Fock backend.
hbar (float): The value of :math:`\hbar` to initialise the circuit with, depending on the conventions followed.
By default, :math:`\hbar=2`. See :ref:`conventions` for more details.
pure (bool): whether to begin the circuit in a pure state representation
"""
# pylint: disable=attribute-defined-outside-init
if cutoff_dim is None:
raise ValueError(
"Argument 'cutoff_dim' must be passed to the Fock backend")
elif not isinstance(cutoff_dim, int):
raise ValueError(
"Argument 'cutoff_dim' must be a positive integer")
elif not isinstance(num_subsystems, int):
raise ValueError(
"Argument 'num_subsystems' must be a positive integer")
elif not isinstance(pure, bool):
raise ValueError("Argument 'pure' must be either True or False")
self._init_modes = num_subsystems
self.qreg = QReg(num_subsystems, cutoff_dim, hbar, pure)
self._modeMap = ModeMap(num_subsystems)
def begin_circuit(self, num_subsystems, **kwargs):
r"""Instantiate a quantum circuit.
Instantiates a representation of a quantum optical state with ``num_subsystems`` modes.
The state is initialized to vacuum.
The modes in the circuit are indexed sequentially using integers, starting from zero.
Once an index is assigned to a mode, it can never be re-assigned to another mode.
If the mode is deleted its index becomes invalid.
An operation acting on an invalid or unassigned mode index raises an ``IndexError`` exception.
Args:
num_subsystems (int): number of modes in the circuit
Keyword Args:
cutoff_dim (int): Numerical Hilbert space cutoff dimension for the modes.
For each mode, the simulator can represent the Fock states :math:`\ket{0}, \ket{1}, \ldots, \ket{\text{cutoff_dim}-1}`.
pure (bool): If True (default), use a pure state representation (otherwise will use a mixed state representation).
"""
cutoff_dim = kwargs.get('cutoff_dim', None)
pure = kwargs.get('pure', True)
if cutoff_dim is None:
raise ValueError("Argument 'cutoff_dim' must be passed to the Fock backend")
if not isinstance(cutoff_dim, int):
raise ValueError("Argument 'cutoff_dim' must be a positive integer")
if not isinstance(num_subsystems, int):
raise ValueError("Argument 'num_subsystems' must be a positive integer")
if not isinstance(pure, bool):
raise ValueError("Argument 'pure' must be either True or False")
self._init_modes = num_subsystems
self.circuit = Circuit(num_subsystems, cutoff_dim, pure)
self._modemap = ModeMap(num_subsystems)
def begin_circuit(self,
num_subsystems,
*,
cutoff_dim=None,
pure=True,
**kwargs):
r"""
Create a quantum circuit (initialized in vacuum state) with the number of modes
equal to num_subsystems and a Fock-space cutoff dimension of cutoff_dim.
Args:
num_subsystems (int): number of modes the circuit should begin with
cutoff_dim (int): numerical cutoff dimension in Fock space for each mode.
``cutoff_dim=D`` represents the Fock states :math:`|0\rangle,\dots,|D-1\rangle`.
This argument is **required** for the Fock backend.
pure (bool): whether to begin the circuit in a pure state representation
"""
# pylint: disable=attribute-defined-outside-init
if cutoff_dim is None:
raise ValueError(
"Argument 'cutoff_dim' must be passed to the Fock backend")
if not isinstance(cutoff_dim, int):
raise ValueError(
"Argument 'cutoff_dim' must be a positive integer")
if not isinstance(num_subsystems, int):
raise ValueError(
"Argument 'num_subsystems' must be a positive integer")
if not isinstance(pure, bool):
raise ValueError("Argument 'pure' must be either True or False")
self._init_modes = num_subsystems
self.circuit = Circuit(num_subsystems, cutoff_dim, pure)
self._modemap = ModeMap(num_subsystems)
def begin_circuit(self,
num_subsystems,
cutoff_dim=None,
hbar=2,
pure=True,
**kwargs):
r"""Create a quantum circuit (initialized in vacuum state) with the number of modes
equal to num_subsystems and a Fock-space cutoff dimension of cutoff_dim.
Args:
num_subsystems (int): number of modes the circuit should begin with
cutoff_dim (int): numerical cutoff dimension in Fock space for each mode.
``cutoff_dim=D`` represents the Fock states :math:`|0\rangle,\dots,|D-1\rangle`.
This argument is **required** for the Tensorflow backend.
hbar (float): The value of :math:`\hbar` to initialise the circuit with, depending on the conventions followed.
By default, :math:`\hbar=2`. See :ref:`conventions` for more details.
pure (bool): whether to begin the circuit in a pure state representation
**kwargs: optional keyword arguments which will be passed to the underlying circuit class
* **batch_size** (*None* or *int*): the size of the batch-axis dimension. If None, no batch-axis will be used.
"""
# pylint: disable=too-many-arguments,attribute-defined-outside-init
with tf.name_scope('Begin_circuit'):
batch_size = kwargs.get('batch_size', None)
if cutoff_dim is None:
raise ValueError(
"Argument 'cutoff_dim' must be passed to the Tensorflow backend"
)
if not isinstance(num_subsystems, int):
raise ValueError(
"Argument 'num_subsystems' must be a positive integer")
elif not isinstance(cutoff_dim, int):
raise ValueError(
"Argument 'cutoff_dim' must be a positive integer")
elif not isinstance(pure, bool):
raise ValueError(
"Argument 'pure' must be either True or False")
elif batch_size == 1:
raise ValueError(
"batch_size of 1 not supported, please use different batch_size or set batch_size=None"
)
else:
self._modemap = ModeMap(num_subsystems)
circuit = Circuit(self._graph, num_subsystems, cutoff_dim,
hbar, pure, batch_size)
self._init_modes = num_subsystems
self.circuit = circuit
def begin_circuit(self, num_subsystems, **kwargs):
r"""Instantiate a quantum circuit.
Instantiates a representation of a quantum optical state with ``num_subsystems`` modes.
The state is initialized to vacuum.
The modes in the circuit are indexed sequentially using integers, starting from zero.
Once an index is assigned to a mode, it can never be re-assigned to another mode.
If the mode is deleted its index becomes invalid.
An operation acting on an invalid or unassigned mode index raises an ``IndexError`` exception.
Args:
num_subsystems (int): number of modes in the circuit
Keyword Args:
cutoff_dim (int): Numerical Hilbert space cutoff dimension for the modes.
For each mode, the simulator can represent the Fock states :math:`\ket{0}, \ket{1}, \ldots, \ket{\text{cutoff_dim}-1}`.
pure (bool): If True (default), use a pure state representation (otherwise will use a mixed state representation).
batch_size (None or int): Size of the batch-axis dimension. If None, no batch-axis will be used.
dtype (tf.DType): Complex Tensorflow Tensor type representation, either ``tf.complex64`` (default) or ``tf.complex128``.
Note, ``tf.complex128`` will increase memory usage substantially.
"""
cutoff_dim = kwargs.get("cutoff_dim", None)
pure = kwargs.get("pure", True)
batch_size = kwargs.get("batch_size", None)
dtype = kwargs.get("dtype", tf.complex64)
if cutoff_dim is None:
raise ValueError("Argument 'cutoff_dim' must be passed to the TensorFlow backend")
if not isinstance(num_subsystems, int):
raise ValueError("Argument 'num_subsystems' must be a positive integer")
if not isinstance(cutoff_dim, int):
raise ValueError("Argument 'cutoff_dim' must be a positive integer")
if not isinstance(pure, bool):
raise ValueError("Argument 'pure' must be either True or False")
if not dtype in (tf.complex64, tf.complex128):
raise ValueError("Argument 'dtype' must be a complex Tensorflow DType")
if batch_size == 1:
raise ValueError(
"batch_size of 1 not supported, please use different batch_size or set batch_size=None"
)
with tf.name_scope("Begin_circuit"):
self._modemap = ModeMap(num_subsystems)
circuit = Circuit(num_subsystems, cutoff_dim, pure, batch_size, dtype)
self._init_modes = num_subsystems
self.circuit = circuit