# qiskit.quantum_info.average_gate_fidelity¶

average_gate_fidelity(channel, target=None, require_cp=True, require_tp=False)[Quellcode]

Return the average gate fidelity of a noisy quantum channel.

The average gate fidelity $$F_{\text{ave}}$$ is given by

$\begin{split}F_{\text{ave}}(\mathcal{E}, U) &= \int d\psi \langle\psi|U^\dagger \mathcal{E}(|\psi\rangle\!\langle\psi|)U|\psi\rangle \\ &= \frac{d F_{\text{pro}}(\mathcal{E}, U) + 1}{d + 1}\end{split}$

where $$F_{\text{pro}}(\mathcal{E}, U)$$ is the process_fidelity() of the input quantum channel $$\mathcal{E}$$ with a target unitary $$U$$, and $$d$$ is the dimension of the channel.

Parameter
• channel (QuantumChannel) – noisy quantum channel.

• target (Operator or None) – target unitary operator. If None target is the identity operator [Default: None].

• require_cp (bool) – require channel to be completely-positive [Default: True].

• require_tp (bool) – require channel to be trace-preserving [Default: False].

Rückgabe

The average gate fidelity $$F_{\text{ave}}$$.

Rückgabetyp

float

Verursacht
• QiskitError – if the channel and target do not have the same dimensions, or have different input and output dimensions.

• QiskitError – if the channel and target or are not completely-positive (with require_cp=True) or not trace-preserving (with require_tp=True).