qml.labs.resource_estimation.ResourceQubitUnitary

class ResourceQubitUnitary(num_wires, precision=None, wires=None)[source]

Bases: ResourceOperator

Resource class for the QubitUnitary template.

Parameters:
  • num_wires (int) – the number of qubits the operation acts upon

  • precision (Union[float, None], optional) – The precision used when preparing the single qubit rotations used to synthesize the n-qubit unitary.

  • wires (Sequence[int], optional) – the wires the operation acts on

Resources:

The resources are defined by combining the two equalities in Möttönen and Vartiainen (2005), Fig 14 , we can express an \(n\) qubit unitary as four \(n - 1\) qubit unitaries and three multiplexed rotations via ( ResourceSelectPauliRot ). Specifically, the cost is given by:

  • 1-qubit unitary, the cost is approximated as a single RZ rotation.

  • 2-qubit unitary, the cost is approximated as four single qubit rotations and three CNOT gates.

  • 3-qubit unitary or more, the cost is given according to the reference above, recursively.

See also

QubitUnitary

Example

The resources for this operation are computed using:

>>> qu = plre.ResourceQubitUnitary(num_wires=3)
>>> print(plre.estimate_resources(qu, gate_set))
--- Resources: ---
 Total qubits: 3
 Total gates : 52
 Qubit breakdown:
  clean qubits: 0, dirty qubits: 0, algorithmic qubits: 3
 Gate breakdown:
  {'RZ': 24, 'CNOT': 24, 'RY': 4}

num_wires

resource_keys

resource_params

Returns a dictionary containing the minimal information needed to compute the resources.

num_wires = 0
resource_keys = {'num_wires', 'precision'}
resource_params

Returns a dictionary containing the minimal information needed to compute the resources.

Returns:

A dictionary containing the resource parameters:
  • num_wires (int): the number of qubits the operation acts upon

  • precision (Union[float, None], optional): The precision used when preparing the single qubit rotations used to synthesize the n-qubit unitary.

Return type:

dict

adjoint_resource_decomp(*args, **kwargs)

Returns a list of actions that define the resources of the operator.

controlled_resource_decomp(...)

Returns a list representing the resources for a controlled version of the operator.

default_adjoint_resource_decomp(*args, **kwargs)

Returns a list representing the resources for the adjoint of the operator.

default_controlled_resource_decomp(...)

Returns a list representing the resources for a controlled version of the operator.

default_pow_resource_decomp(pow_z, *args, ...)

Returns a list representing the resources for an operator raised to a power.

default_resource_decomp(num_wires[, precision])

Returns a list representing the resources of the operator.

pow_resource_decomp(pow_z, *args, **kwargs)

Returns a list representing the resources for an operator raised to a power.

queue([context])

Append the operator to the Operator queue.

resource_decomp(*args, **kwargs)

Returns a list of actions that define the resources of the operator.

resource_rep(num_wires, precision)

Returns a compressed representation containing only the parameters of the Operator that are needed to compute the resources.

resource_rep_from_op()

Returns a compressed representation directly from the operator

set_resources(new_func[, override_type])

Set a custom function to override the default resource decomposition.

tracking_name(*args, **kwargs)

Returns a name used to track the operator during resource estimation.

tracking_name_from_op()

Returns the tracking name built with the operator's parameters.

classmethod adjoint_resource_decomp(*args, **kwargs)

Returns a list of actions that define the resources of the operator.

classmethod controlled_resource_decomp(ctrl_num_ctrl_wires, ctrl_num_ctrl_values, *args, **kwargs)

Returns a list representing the resources for a controlled version of the operator.

Parameters:
  • ctrl_num_ctrl_wires (int) – the number of qubits the operation is controlled on

  • ctrl_num_ctrl_values (int) – the number of control qubits, that are controlled when in the \(|0\rangle\) state

classmethod default_adjoint_resource_decomp(*args, **kwargs)

Returns a list representing the resources for the adjoint of the operator.

classmethod default_controlled_resource_decomp(ctrl_num_ctrl_wires, ctrl_num_ctrl_values, *args, **kwargs)

Returns a list representing the resources for a controlled version of the operator.

Parameters:
  • ctrl_num_ctrl_wires (int) – the number of qubits the operation is controlled on

  • ctrl_num_ctrl_values (int) – the number of control qubits, that are controlled when in the \(|0\rangle\) state

classmethod default_pow_resource_decomp(pow_z, *args, **kwargs)

Returns a list representing the resources for an operator raised to a power.

Parameters:

pow_z (int) – exponent that the operator is being raised to

classmethod default_resource_decomp(num_wires, precision=None, **kwargs)[source]

Returns a list representing the resources of the operator. Each object in the list represents a gate and the number of times it occurs in the circuit.

Parameters:
  • num_wires (int) – the number of qubits the operation acts upon

  • precision (Union[float, None], optional) – The precision used when preparing the single qubit rotations used to synthesize the n-qubit unitary.

Resources:

The resources are defined by combining the two equalities in Möttönen and Vartiainen (2005), Fig 14, we can express an \(n\)- qubit unitary as four \(n - 1\)-qubit unitaries and three multiplexed rotations via (ResourceSelectPauliRot). Specifically, the cost is given by:

  • 1-qubit unitary, the cost is approximated as a single RZ rotation.

  • 2-qubit unitary, the cost is approximated as four single qubit rotations and three CNOT gates.

  • 3-qubit unitary or more, the cost is given according to the reference above, recursively.

Returns:

A list of GateCount objects, where each object represents a specific quantum gate and the number of times it appears in the decomposition.

Return type:

list[GateCount]

classmethod pow_resource_decomp(pow_z, *args, **kwargs)

Returns a list representing the resources for an operator raised to a power.

Parameters:

pow_z (int) – exponent that the operator is being raised to

queue(context=<class 'pennylane.queuing.QueuingManager'>)

Append the operator to the Operator queue.

classmethod resource_decomp(*args, **kwargs)

Returns a list of actions that define the resources of the operator.

classmethod resource_rep(num_wires, precision)[source]

Returns a compressed representation containing only the parameters of the Operator that are needed to compute the resources.

Parameters:
  • num_wires (int) – the number of qubits the operation acts upon

  • precision (Union[float, None], optional) – The precision used when preparing the single qubit rotations used to synthesize the n-qubit unitary.

Returns:

the operator in a compressed representation

Return type:

CompressedResourceOp

resource_rep_from_op()

Returns a compressed representation directly from the operator

classmethod set_resources(new_func, override_type='base')

Set a custom function to override the default resource decomposition.

This method allows users to replace any of the resource_decomp, adjoint_resource_decomp, ctrl_resource_decomp, or pow_resource_decomp methods globally for every instance of the class.

classmethod tracking_name(*args, **kwargs)

Returns a name used to track the operator during resource estimation.

tracking_name_from_op()

Returns the tracking name built with the operator’s parameters.