uniqc.simulator.qutip_sim_impl module

QuTiP-backed density matrix simulator implementation.

This module provides a density-matrix quantum simulator implementation using QuTiP, supporting unitary operations, Kraus channels, and measurement for noisy quantum simulation.

Key exports:

  • DensityOperatorSimulatorQutip: Density-matrix simulator backed by QuTiP.

class uniqc.simulator.qutip_sim_impl.DensityOperatorSimulatorQutip[source]

Bases: object

Density-matrix simulator backed by QuTiP.

amplitude_damping(qubit, gamma)[source]

Apply amplitude damping noise.

Parameters:

  • qubit (int) – Target qubit index.

  • gamma (float) – Damping rate (0 to 1).

Return type:

None

bitflip(qubit, p)[source]

Apply bit-flip (X) noise.

Parameters:

  • qubit (int) – Target qubit index.

  • p (float) – Bit-flip probability.

Return type:

None

cnot(control_qubit, target_qubit, control_qubits_set=None, is_dagger=False)[source]

Apply the CNOT (controlled-NOT) gate.

Parameters:

  • control_qubit (int) – Control qubit index.

  • target_qubit (int) – Target qubit index.

  • control_qubits_set (list[int] | None) – Additional control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

cswap(control_qubit, q1, q2, control_qubits_set=None, is_dagger=False)[source]

Apply the CSWAP (Fredkin) gate.

Parameters:

  • control_qubit (int) – Control qubit index.

  • q1 (int) – First target qubit index.

  • q2 (int) – Second target qubit index.

  • control_qubits_set (list[int] | None) – Additional control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

cz(qubit1, qubit2, control_qubits_set=None, is_dagger=False)[source]

Apply the CZ (controlled-Z) gate.

Parameters:

  • qubit1 (int) – First qubit index.

  • qubit2 (int) – Second qubit index.

  • control_qubits_set (list[int] | None) – Additional control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

density_matrix: Qobj | None
depolarizing(qubit, p)[source]

Apply depolarizing noise to a single qubit.

Parameters:

  • qubit (int) – Target qubit index.

  • p (float) – Depolarizing probability.

Return type:

None

hadamard(qubit, control_qubits_set=None, is_dagger=False)[source]

Apply the Hadamard gate.

Parameters:

  • qubit (int) – Target qubit index.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

init_n_qubit(n)[source]

Initialize the simulator with n qubits in the |0...0> state.

Parameters:

n (int)

Return type:

None

iswap(q1, q2, control_qubits_set=None, is_dagger=False)[source]

Apply the iSWAP gate.

Parameters:

  • q1 (int) – First qubit index.

  • q2 (int) – Second qubit index.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

kraus1q(qubit, parameters)[source]

Apply single-qubit Kraus noise.

Parameters:

  • qubit (int) – Target qubit index.

  • parameters (list[list[float]]) – List of Kraus operator matrix elements (flattened 2x2).

Return type:

None

kraus2q(q1, q2, parameters)[source]

Apply two-qubit Kraus noise.

Parameters:

  • q1 (int) – First qubit index.

  • q2 (int) – Second qubit index.

  • parameters (list[list[float]]) – List of Kraus operator matrix elements (flattened 4x4).

Return type:

None

n_qubits: int
pauli_error_1q(qubit, px, py, pz)[source]

Apply single-qubit Pauli error.

Parameters:

  • qubit (int) – Target qubit index.

  • px (float) – Probability of X error.

  • py (float) – Probability of Y error.

  • pz (float) – Probability of Z error.

Return type:

None

pauli_error_2q(q1, q2, parameters)[source]

Two-qubit Pauli error with 15 independent probabilities.

Parameters:

  • q1 (int) – qubit 1 index

  • q2 (int) – qubit 2 index

  • parameters (list[float] | tuple[float, ...]) – list of 15 probabilities

Return type:

None

phase2q(q1, q2, theta1, theta2, theta3, control_qubits_set=None, is_dagger=False)[source]

Phase2Q gate: u1(q1, theta1), u1(q2, theta2), zz(q1, q2, theta3).

Parameters:
Return type:

None

phaseflip(qubit, prob)[source]

Apply phase-flip (Z) noise.

Parameters:

  • qubit (int) – Target qubit index.

  • prob (float) – Phase-flip probability.

Return type:

None

pmeasure(measure_qubits)[source]

Compute measurement probabilities for the given qubits.

Parameters:

measure_qubits (list[int])

Return type:

list[float]

rphi(qubit, theta, phi, control_qubits_set=None, is_dagger=False)[source]

Apply the RPhi gate (rotation around axis in XY plane).

Parameters:

  • qubit (int) – Target qubit index.

  • theta (float) – Polar angle in radians.

  • phi (float) – Azimuthal angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

rphi180(qubit, phi, control_qubits_set=None, is_dagger=False)[source]

Apply the RPhi180 gate (π rotation around axis in XY plane).

Parameters:

  • qubit (int) – Target qubit index.

  • phi (float) – Azimuthal angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

rphi90(qubit, phi, control_qubits_set=None, is_dagger=False)[source]

Apply the RPhi90 gate (π/2 rotation around axis in XY plane).

Parameters:

  • qubit (int) – Target qubit index.

  • phi (float) – Azimuthal angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

rx(qubit, theta, control_qubits_set=None, is_dagger=False)[source]

Apply the RX gate.

Parameters:

  • qubit (int) – Target qubit index.

  • theta (float) – Rotation angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits for controlled rotation.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

ry(qubit, theta, control_qubits_set=None, is_dagger=False)[source]

Apply the RY gate.

Parameters:

  • qubit (int) – Target qubit index.

  • theta (float) – Rotation angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits for controlled rotation.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

rz(qubit, theta, control_qubits_set=None, is_dagger=False)[source]

Apply the RZ gate.

Parameters:

  • qubit (int) – Target qubit index.

  • theta (float) – Rotation angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits for controlled rotation.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

s(qubit, control_qubits_set=None, is_dagger=False)[source]

Apply the S gate (phase gate, π/2).

Parameters:

  • qubit (int) – Target qubit index.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

property state: ndarray

Return the density matrix as a NumPy array.

stateprob()[source]

Return the diagonal of the density matrix (state probabilities).

Return type:

ndarray

swap(qubit1, qubit2, control_qubits_set=None, is_dagger=False)[source]

Apply the SWAP gate.

Parameters:

  • qubit1 (int) – First qubit index.

  • qubit2 (int) – Second qubit index.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

sx(qubit, control_qubits_set=None, is_dagger=False)[source]

Apply the SX (square-root of X) gate.

Parameters:

  • qubit (int) – Target qubit index.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

t(qubit, control_qubits_set=None, is_dagger=False)[source]

Apply the T gate (π/4 phase gate).

Parameters:

  • qubit (int) – Target qubit index.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

toffoli(c1, c2, target, control_qubits_set=None, is_dagger=False)[source]

Apply the Toffoli (CCNOT) gate.

Parameters:

  • c1 (int) – First control qubit index.

  • c2 (int) – Second control qubit index.

  • target (int) – Target qubit index.

  • control_qubits_set (list[int] | None) – Additional control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

twoqubit_depolarizing(q1, q2, p)[source]

Apply two-qubit depolarizing noise.

Parameters:

  • q1 (int) – First qubit index.

  • q2 (int) – Second qubit index.

  • p (float) – Depolarizing probability.

Return type:

None

u1(qubit, theta, control_qubits_set=None, is_dagger=False)[source]

Apply the U1 gate.

Parameters:

  • qubit (int) – Target qubit index.

  • theta (float) – Phase angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

u2(qubit, phi, lam, control_qubits_set=None, is_dagger=False)[source]

Apply the U2 gate.

Parameters:

  • qubit (int) – Target qubit index.

  • phi (float) – First phase angle in radians.

  • lam (float) – Second phase angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

u3(qubit, theta, phi, lam, control_qubits_set=None, is_dagger=False)[source]

Apply the U3 gate.

Parameters:

  • qubit (int) – Target qubit index.

  • theta (float) – Polar angle in radians.

  • phi (float) – First phase angle in radians.

  • lam (float) – Second phase angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

uu15(q1, q2, params, control_qubits_set=None, is_dagger=False)[source]

U15 gate using KAK decomposition.

Parameters:

  • q1 (int) – qubit 1 index

  • q2 (int) – qubit 2 index

  • params (list[float]) – list of 15 parameters

  • control_qubits_set (list[int] | None) – list of control qubits

  • is_dagger (bool) – whether to apply daggered gate

Return type:

None

x(qubit, control_qubits_set=None, is_dagger=False)[source]

Apply the X (NOT) gate.

Parameters:

  • qubit (int) – Target qubit index.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

xx(q1, q2, theta, control_qubits_set=None, is_dagger=False)[source]

Apply the XX interaction gate.

Parameters:

  • q1 (int) – First qubit index.

  • q2 (int) – Second qubit index.

  • theta (float) – Interaction angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

xy(q1, q2, theta, control_qubits_set=None, is_dagger=False)[source]

Apply the XY interaction gate.

Parameters:

  • q1 (int) – First qubit index.

  • q2 (int) – Second qubit index.

  • theta (float) – Interaction angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

y(qubit, control_qubits_set=None, is_dagger=False)[source]

Apply the Y gate.

Parameters:

  • qubit (int) – Target qubit index.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

yy(q1, q2, theta, control_qubits_set=None, is_dagger=False)[source]

Apply the YY interaction gate.

Parameters:

  • q1 (int) – First qubit index.

  • q2 (int) – Second qubit index.

  • theta (float) – Interaction angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

z(qubit, control_qubits_set=None, is_dagger=False)[source]

Apply the Z gate.

Parameters:

  • qubit (int) – Target qubit index.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None

zz(q1, q2, theta, control_qubits_set=None, is_dagger=False)[source]

Apply the ZZ interaction gate.

Parameters:

  • q1 (int) – First qubit index.

  • q2 (int) – Second qubit index.

  • theta (float) – Interaction angle in radians.

  • control_qubits_set (list[int] | None) – Control qubits.

  • is_dagger (bool) – Whether to apply the dagger version.

Return type:

None