diff --git a/cirq-core/cirq/ops/common_channels.py b/cirq-core/cirq/ops/common_channels.py index 63482610eda..7f28231becf 100644 --- a/cirq-core/cirq/ops/common_channels.py +++ b/cirq-core/cirq/ops/common_channels.py @@ -37,10 +37,10 @@ class AsymmetricDepolarizingChannel(raw_types.Gate): This channel evolves a density matrix via $$ - \sum_i p_i Pi \rho Pi + \sum_i p_i P_i \rho P_i $$ - where i varies from 0 to $4^n-1$ and Pi represents n-qubit Pauli operator + where i varies from $0$ to $4^n-1$ and $P_i$ represents n-qubit Pauli operator (including identity). The input $\rho$ is the density matrix before the depolarization. @@ -217,10 +217,10 @@ def asymmetric_depolarize( This channel evolves a density matrix via $$ - \sum_i p_i Pi \rho Pi + \sum_i p_i P_i \rho P_i $$ - where i varies from 0 to $4^n-1$ and Pi represents n-qubit Pauli operator + where i varies from $0$ to $4^n-1$ and $P_i$ represents n-qubit Pauli operator (including identity). The input $\rho$ is the density matrix before the depolarization. @@ -1079,7 +1079,7 @@ class BitFlipChannel(raw_types.Gate): This channel evolves a density matrix via: $$ - \rho \rightarrow M_0 \rho M_0^\dagger + M_1 \rho M_1^\dagger + \rho \rightarrow M_0 \rho M_0^\dagger + M_1 \rho M_1^\dagger $$ With: