ShiftGate

class ShiftGate[source]

Bases: ConstantGate, QuditGate

The one-qudit shift (X) gate. This is a Weyl-Heisenberg gate.

This gate shifts the state of a qudit up by one level modulo. For example, the shift gate on a qubit is the Pauli-X gate. The shift gate on a qutrit is the following matrix:

\begin{pmatrix} 0 & 0 & 1 \\ 1 & 0 & 0 \\ 0 & 1 & 0 \\ \end{pmatrix}

The shift gate is generally given by the following formula:

where d is the number of levels (2 levels is a qubit, 3 levels is a qutrit, etc.)

References

__init__(radix=2)[source]

Construct a ShiftGate.

Parameters:

radix (int) – The number of qudit levels (>=2). Defaults to qutrits.

Raises:

ValueError – if radix < 2

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

check_env_matrix(env_matrix)

Check to ensure the env_matrix is validly shaped.

check_parameters(params)

Check parameters are valid and match the unitary.

get_grad([params])

Return the gradient for this gate.

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, see Unitary for more.

get_unitary_and_grad([params])

Return the unitary and gradient for this gate.

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.

optimize(env_matrix)

Return the optimal parameters with respect to an environment matrix.

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.