bit_flip_mixer¶

bit_flip_mixer(graph, b)[source]¶

Bit-flip mixer over graph (per Hadfield et al. 2019).

For each vertex v with neighbour set N(v) of degree d(v):

\[\frac{1}{2^{d(v)}} X_v \prod_{w \in N(v)} (I + (-1)^b Z_w)\]

expanded into 2^{d(v)} Pauli terms per vertex.

The graph nodes must be non-negative integer qubit indices.