spin_pulse.transpilation.pulse_layer

Layer of pulses applied to the target qubits simultaneously.

Classes

PulseLayer

Layer of one- and two-qubit gate pulse sequences.

Module Contents

class spin_pulse.transpilation.pulse_layer.PulseLayer(qubits, oneq_pulse_sequences, twoq_pulse_sequences)

Layer of one- and two-qubit gate pulse sequences.

A PulseLayer groups single-qubit and two-qubit PulseSequence objects that act over a common time interval. Pulse sequences in the layer are eventually padded with idle instructions such that all of them share the same duration. The layer keeps track of which qubits are driven by one-qubit or two-qubit pulses and which qubits remain idle.

- duration

Duration of the layer, which is the maximal duration of the pulse sequences given.

Type:

int

- qubits

Ordered list of qubits included in the layer.

Type:

list[qiskit.circuit.Qubit]

- num_qubits

Number of qubits in the layer.

Type:

int

- oneq_pulse_sequences

One-qubit pulse sequence assigned to each qubit. For qubits without an explicit drive, an idle-only PulseSequence of length duration is created.

Type:

list[PulseSequence]

- twoq_pulse_sequences

Two-qubit pulse sequences acting on pair of qubits in the layer.

Type:

list[PulseSequence]

- pulse_sequences

Concatenation of all one- and two-qubit pulse sequences in the layer.

Type:

list[PulseSequence]

- n_pulses

Total number of pulse sequences in the layer.

Type:

int

- qubits_oneq_active

Qubits that are manipulated during the layer through single-qubit gate.

Type:

list[qiskit.circuit.Qubit]

- qubits_twoq_active

Qubits that are manipulated during the layer through two-qubit gate.

Type:

list[qiskit.circuit.Qubit]

- qubits_idle

Qubits that are idle during this layer.

Type:

list[qiskit.circuit.Qubit]

Initialize the PulseLayer from lists of pulse sequences and qubits.

Parameters:

• qubits (list[qiskit.circuit.Qubit]) – Ordered list of qubits included in the layer.

• oneq_pulse_sequences (list[PulseSequence]) – One-qubit pulse sequences to be applied in the layer.

• twoq_pulse_sequences (list[PulseSequence]) – Two-qubit pulse sequences to be applied in the layer.

duration

oneq_pulse_sequences

twoq_pulse_sequences

pulse_sequences

qubits

n_pulses: int

num_qubits: int

qubits_oneq_active = []

qubits_twoq_active = []

qubits_idle = []

classmethod from_circuit_layer(qubits, circuit_layer, hardware_specs)

Construct a PulseLayer from a circuit layer.

This method converts each gate in a circuit layer into a PulseSequence object according to the hardware specifications. Single- and two-qubit gates are translated separately, and the resulting pulse sequences are grouped into a PulseLayer.

Parameters:

• qubits (list[qiskit.circuit.Qubit]) – Ordered list of qubits included in the layer.

• circuit_layer (QuantumCircuit) – QuantumCircuit instance representing one layer of a bigger circuit. Its instructions are passed to gate_to_pulse_sequences to be converted into pulses.

• hardware_specs (HardwareSpecs) – HardwareSpecs class instance that defines the hardware specifications.

Returns:

A PulseLayer containing the pulse sequences that corresponds to the circuit_layer.

Return type:

PulseLayer

plot(axs=None, label_gates=True)

Plot all single-qubit and two-qubit pulse sequences in the layer.

For each qubit, the corresponding one-qubit PulseSequence is displayed on its own axis. Two-qubit PulseSequences are plotted on intermediate axes between the qubits they act on. If no axis array is provided, a new matplotlib figure is created.

Parameters:

• axs (list[Axes] | None) – Array of axes on which to draw the sequences. If None, a new figure and axis array is created.

• label_gates (bool | str) – Controls gate labelling. If True, each pulse is annotated with a default gate label. If a string, the value is forwarded to the underlying PulseSequence.plot methods to customize labelling.

to_circuit()

Convert the pulse layer into an equivalent qiskit.QuantumCircuit.

Each PulseSequence is translated into a unitary matrix by propagating the corresponding Hamiltonian terms over the layer duration. Two-qubit sequences generate 4x4 unitaries, while single-qubit sequences generate 2x2 unitaries. The resulting unitaries are appended to a new qiskit.QuantumCircuit in an order consistent with the layer structure.

Returns:

A circuit representation of the pulse layer, where UnitaryGate

corresponds to a pulse sequence.

Return type:

qiskit.QuantumCircuit

attach_dynamical_decoupling(hardware_specs)

Apply a dynamical decoupling sequence to all one-qubit pulse sequences if possible.

If a dynamical decoupling mode is specified in the hardware specifications, this method transforms each one-qubit PulseSequence in the layer with a new sequence obtained by applying a dynamical decoupling transformation according to the specified hardware parameters. Two-qubit sequences are left unchanged.

Parameters:

hardware_specs (HardwareSpecs) – Hardware configuration specifying the dynamical decoupling mode and available pulse shapes.

Return type:

None