QulacsCircuit¶

class QulacsCircuit¶

Qulacs-based quantum circuit implementation.

Wraps QuantumCircuit and Observable from Qulacs to satisfy the circuit protocol interface required by QAOA circuit construction.

Methods

`__init__`
`add_cnot_gate`	Apply a CNOT gate with control qubit i and target qubit j.
`add_cz_gate`	Apply a controlled-Z gate between qubit i and qubit j.
`add_h_gate`	Apply a Hadamard gate to qubit i.
`add_observable_rotation_gate`	Apply a Hamiltonian evolution gate `exp(-i * value * H)`.
`add_p_gate`	Apply a phase gate to qubit i.
`add_rx_gate`	Apply an Rx rotation gate to qubit i.
`add_ry_gate`	Apply an Ry rotation gate to qubit i.
`add_rz_gate`	Apply an Rz rotation gate to qubit i.
`add_s_gate`	Apply an S gate to qubit i, inducing a pi/2 phase on the \|1> state.
`add_sdg_gate`	Apply the adjoint of the S gate to qubit i, inducing a -pi/2 phase on the \|1> state.
`add_swap_gate`	Apply a SWAP gate between qubit i and qubit j.
`add_sx_gate`	Apply a sqrt(X) gate to qubit i.
`add_sxdg_gate`	Apply the adjoint of the sqrt(X) gate to qubit i.
`add_t_gate`	Apply a T gate to qubit i, inducing a pi/4 phase on the \|1> state.
`add_tdg_gate`	Apply the adjoint of the T gate to qubit i, inducing a -pi/4 phase on the \|1> state.
`add_u_gate`	Apply a general single-qubit unitary gate to qubit i.
`add_x_gate`	Apply a Pauli-X gate to qubit i.
`add_y_gate`	Apply a Pauli-Y gate to qubit i.
`add_z_gate`	Apply a Pauli-Z gate to qubit i.
`get_observable_class`	Return the observable implementation class used by this circuit.

Attributes

`num_qubits`	Number of qubits in the circuit.
`raw`	Underlying Qulacs `QuantumCircuit` object.

class QulacsObservable¶

Observable builder backed by Observable from Qulacs.

Accumulates Pauli-X and Pauli-Z terms to construct a Hamiltonian used as the generator of a unitary rotation gate.

__init__(num_qubits: int, _obs: Observable | None = None) → None¶

add_pauli_x(num_qubits: int, bit_index: int, value: float) → Self¶

add_pauli_x(num_qubits: int, bit_index: Iterable[int], value: float) → Self

Add a weighted Pauli-X term acting on the specified qubit(s).

Parameters:

num_qubits (int) – Total number of qubits in the operator (unused for Qulacs).
bit_index (int | Iterable[int]) – Qubit index or indices for the X operator.
value (float) – Coefficient of the term.

Returns:

This instance, for chaining.

Return type:

Self

add_pauli_y(num_qubits: int, bit_index: int, value: float) → Self¶

add_pauli_y(num_qubits: int, bit_index: Iterable[int], value: float) → Self

Add a weighted Pauli-Y term acting on the specified qubit(s).

Parameters:

num_qubits (int) – Total number of qubits in the operator (unused for Qulacs).
bit_index (int | Iterable[int]) – Qubit index or indices for the Y operator.
value (float) – Coefficient of the term.

Returns:

This instance, for chaining.

Return type:

Self

add_pauli_z(num_qubits: int, bit_index: int, value: float) → Self¶

add_pauli_z(num_qubits: int, bit_index: Iterable[int], value: float) → Self

Add a weighted Pauli-Z term acting on the specified qubit(s).

Parameters:

num_qubits (int) – Total number of qubits in the operator (unused for Qulacs).
bit_index (int | Iterable[int]) – Qubit index or indices for the Z operator.
value (float) – Coefficient of the term.

Returns:

This instance, for chaining.

Return type:

Self

property raw: Observable¶: Return the underlying Qulacs Observable.

T_circuit¶: alias of QuantumCircuit

T_obs¶: alias of Observable

classmethod get_observable_class() → type[QulacsObservable]¶: Return the observable implementation class used by this circuit.

__init__(num_qubits: int) → None¶

add_cnot_gate(i: int, j: int) → Self¶

Apply a CNOT gate with control qubit i and target qubit j.

Parameters:

i (int) – Control qubit index.
j (int) – Target qubit index.

Returns:

This instance, for chaining.

Return type:

Self

add_cz_gate(i: int, j: int) → Self¶

Apply a controlled-Z gate between qubit i and qubit j.

Parameters:

i (int) – Control qubit index.
j (int) – Target qubit index.

Returns:

This instance, for chaining.

Return type:

Self

add_h_gate(i: int) → Self¶

Apply a Hadamard gate to qubit i.

Parameters:: i (int) – Target qubit index.
Returns:: This instance, for chaining.
Return type:: Self

add_observable_rotation_gate( op_f: T_obs | ObservableProtocol[T_obs], value: float, num_qubits: int, ) → Self¶

Apply a Hamiltonian evolution gate exp(-i * value * H).

Parameters:

op_f (ObservableProtocol[T_obs]) – Observable whose raw Observable is used as the Hamiltonian H.
value (float) – Evolution time (rotation angle).
num_qubits (int) – Number of qubits the gate acts on (unused for Qulacs).

Returns:

This instance, for chaining.

Return type:

Self

add_p_gate(i: int, value: float) → Self¶

Apply a phase gate to qubit i.

Parameters:

i (int) – Target qubit index.
value (float) – Phase angle in radians.

Returns:

This instance, for chaining.

Return type:

Self

add_rx_gate(i: int, value: float) → Self¶

Apply an Rx rotation gate to qubit i.

Parameters:

i (int) – Target qubit index.
value (float) – Rotation angle in radians.

Returns:

This instance, for chaining.

Return type:

Self

add_ry_gate(i: int, value: float) → Self¶

Apply an Ry rotation gate to qubit i.

Parameters:

i (int) – Target qubit index.
value (float) – Rotation angle in radians.

Returns:

This instance, for chaining.

Return type:

Self

add_rz_gate(i: int, value: float) → Self¶

Apply an Rz rotation gate to qubit i.

Parameters:

i (int) – Target qubit index.
value (float) – Rotation angle in radians.

Returns:

This instance, for chaining.

Return type:

Self

add_s_gate(i: int) → Self¶

Apply an S gate to qubit i, inducing a pi/2 phase on the |1> state.

Parameters:: i (int) – Target qubit index.
Returns:: This instance, for chaining.
Return type:: Self

add_sdg_gate(i: int) → Self¶

Apply the adjoint of the S gate to qubit i, inducing a -pi/2 phase on the |1> state.

Parameters:: i (int) – Target qubit index.
Returns:: This instance, for chaining.
Return type:: Self

add_swap_gate(i: int, j: int) → Self¶

Apply a SWAP gate between qubit i and qubit j.

Parameters:

i (int) – First qubit index.
j (int) – Second qubit index.

Returns:

This instance, for chaining.

Return type:

Self

add_sx_gate(i: int) → Self¶

Apply a sqrt(X) gate to qubit i.

Parameters:: i (int) – Target qubit index.
Returns:: This instance, for chaining.
Return type:: Self

add_sxdg_gate(i: int) → Self¶

Apply the adjoint of the sqrt(X) gate to qubit i.

Parameters:: i (int) – Target qubit index.
Returns:: This instance, for chaining.
Return type:: Self

add_t_gate(i: int) → Self¶

Apply a T gate to qubit i, inducing a pi/4 phase on the |1> state.

Parameters:: i (int) – Target qubit index.
Returns:: This instance, for chaining.
Return type:: Self

add_tdg_gate(i: int) → Self¶

Apply the adjoint of the T gate to qubit i, inducing a -pi/4 phase on the |1> state.

Parameters:: i (int) – Target qubit index.
Returns:: This instance, for chaining.
Return type:: Self

add_u_gate(i: int, theta: float, phi: float, lam: float) → Self¶

Apply a general single-qubit unitary gate to qubit i.

Parameters:

i (int) – Target qubit index.
theta (float) – First Euler angle in radians.
phi (float) – Second Euler angle in radians.
lam (float) – Third Euler angle in radians.

Returns:

This instance, for chaining.

Return type:

Self

add_x_gate(i: int) → Self¶

Apply a Pauli-X gate to qubit i.

Parameters:: i (int) – Target qubit index.
Returns:: This instance, for chaining.
Return type:: Self

add_y_gate(i: int) → Self¶

Apply a Pauli-Y gate to qubit i.

Parameters:: i (int) – Target qubit index.
Returns:: This instance, for chaining.
Return type:: Self

add_z_gate(i: int) → Self¶

Apply a Pauli-Z gate to qubit i.

Parameters:: i (int) – Target qubit index.
Returns:: This instance, for chaining.
Return type:: Self

property num_qubits: int¶: Number of qubits in the circuit.

property raw: QuantumCircuit¶: Underlying Qulacs QuantumCircuit object.