UnitaryBuilder

class UnitaryBuilder(num_qudits, radixes=[])

Bases: Unitary

An object for fast unitary accumulation using tensor networks.

A UnitaryBuilder is similar to a StringBuilder in the sense that it is an efficient way to string together or accumulate Unitary objects. This class uses concepts from tensor networks to efficiently multiply unitary matrices.

__init__(num_qudits, radixes=[])

UnitaryBuilder constructor.

Parameters:

• num_qudits (int) – The number of qudits to build a Unitary for.

• radixes (Sequence[int]) – A sequence with its length equal to num_qudits. Each element specifies the base of a qudit. Defaults to qubits.

Raises:

• ValueError – If num_qudits is nonpositive.

• ValueError – If the length of radixes is not equal to num_qudits.

Examples

>>> builder = UnitaryBuilder(4)  # Creates a 4-qubit builder.

Attributes

dim	The matrix dimension for this unitary.
num_params	The number of real parameters this unitary-valued function takes.
num_qudits	The number of qudits this unitary can act on.
radixes	The number of orthogonal states for each qudit.

Methods

apply_left(utry, location[, inverse, ...])	Apply the specified unitary on the left of this UnitaryBuilder.
apply_right(utry, location[, inverse, ...])	Apply the specified unitary on the right of this UnitaryBuilder.
calc_env_matrix(location)	Calculates the environment matrix w.r.t.
check_parameters(params)	Check parameters are valid and match the unitary.
eval_apply_left(M, location)	Evaluate the application of M on the left of this UnitaryBuilder.
eval_apply_right(M, location)	Evaluate the application of M on the right of this UnitaryBuilder.
get_unitary([params])	Build the unitary, see Unitary.get_unitary() for more.
is_constant()	Return true if this unitary doesn't take parameters.
is_parameterized()	Return true if this unitary is parameterized.
is_qubit_only()	Return true if this unitary can only act on qubits.
is_qudit_only(radix)	Return true if this unitary can only act on radix-qudits.
is_qutrit_only()	Return true if this unitary can only act on qutrits.
is_self_inverse([params])	Checks whether the unitary is its own inverse.