SubSwapGate

class SubSwapGate(radix, qudit_levels)[source]

Bases: QuditGate, CachedClass

The two-qudit subspace SWAP gate.

The subspace SWAP gate swaps between “qudit-levels” on a two-qudit gate. For example, a |01> to |20> swap would be the identity with the |01> row and |20> rows swapped.

__init__(radix, qudit_levels)[source]

Construct a SubSwapGate.

Parameters:

radix (int) – The number of qudit levels (>=2).
qudit_levels (str) – The qudit levels that should be swapped, separated by a comma. Example: “0,1;2,0” to swap |01> to |20>

Raises:

ValueError – if radix < 2
ValueError – If any of the qudit levels integer represenation greater than or equal to radix.
ValueError – If the qudit_levels string is not formatted correctly.

Attributes

`dim`	The matrix dimension for this unitary.
`name`	The name of this gate.
`num_params`	The number of real parameters this unitary-valued function takes.
`num_qudits`	The number of qudits this unitary can act on.
`qasm_name`	The qasm identifier for this gate.
`radix`	The number of levels in each qudit.
`radixes`	The number of orthogonal states for each qudit.

Methods

`calculate_level_swap_expr`(radix, level1, level2)	Build the QGL expression for a qudit level swap.
`calculate_level_swap_unitary`(radix, level1, ...)	Calculate the unitary for a qudit level swap.
`check_parameters`(params)	Check parameters are valid and match the unitary.
`decode_qudit_level_string`(string)	Decode the qudit level string into two pairs of integers.
`get_grad`([params])	Return the gradient for the unitary map as an np.ndarray.
`get_inverse`()	Return the gate's inverse as a gate.
`get_inverse_params`([params])	Return the parameters that invert the gate.
`get_qasm`(params, location)	Returns the qasm string for this gate.
`get_qasm_gate_def`()	Returns a qasm gate definition block for this gate.
`get_unitary`([params])	Return the unitary for this gate.
`get_unitary_and_grad`([params])	Return a tuple combining the outputs of get_unitary and get_grad.
`is_constant`()	Return true if this unitary doesn't take parameters.
`is_differentiable`()	Return true if this gate has a gradient definition.
`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.
`with_all_frozen_params`(params)	Freeze all of a gate's parameters so they don't change from optimization.
`with_frozen_params`(frozen_params)	Freeze some of a gate's parameters so they don't change from optimization.