# qiskit.providers.aer.noise.depolarizing_error¶

depolarizing_error(param, num_qubits, standard_gates=True)[source]

Return a depolarizing quantum error channel.

The depolarizing channel is defined as:

$E(ρ) = (1 - λ) ρ + λ \text{Tr}[ρ] \frac{I}{2^n}$

with $$0 \le λ \le 4^n / (4^n - 1)$$

where $$λ$$ is the depolarizing error param and :mathn is the number of qubits.

• If $$λ = 0$$ this is the identity channel $$E(ρ) = ρ$$

• If $$λ = 1$$ this is a completely depolarizing channel $$E(ρ) = I / 2^n$$

• If $$λ = 4^n / (4^n - 1)$$ this is a uniform Pauli error channel: $$E(ρ) = \sum_j P_j ρ P_j / (4^n - 1)$$ for all $$P_j != I$$.

Paramètres
• param (double) – depolarizing error parameter.

• num_qubits (int) – the number of qubits for the error channel.

• standard_gates (bool) – if True return the operators as standard qobj Pauli gate instructions. If false return as unitary matrix qobj instructions. (Default: True)

Renvoie

The quantum error object.

Type renvoyé

QuantumError

Lève

NoiseError – If noise parameters are invalid.