ZZFeatureMap.get_entangler_map

ZZFeatureMap.get_entangler_map(rep_num, block_num, num_block_qubits)

Get the entangler map for in the repetition rep_num and the block block_num.

The entangler map for the current block is derived from the value of self.entanglement. Below the different cases are listed, where i and j denote the repetition number and the block number, respectively, and n the number of qubits in the block.

entanglement type | entangler map ——————————-+——————————————————– None | [[0, …, n - 1]] str (e.g ‘full’) | the specified connectivity on n qubits List[int] | [entanglement] List[List[int]] | entanglement List[List[List[int]]] | entanglement[i] List[List[List[List[int]]]] | entanglement[i][j] List[str] | the connectivity specified in entanglement[i] List[List[str]] | the connectivity specified in entanglement[i][j] Callable[int, str] | same as List[str] Callable[int, List[List[int]]] | same as List[List[List[int]]]

Note that all indices are to be taken modulo the length of the array they act on, i.e. no out-of-bounds index error will be raised but we re-iterate from the beginning of the list.

Parameters

  • rep_num (int) – The current repetition we are in.

  • block_num (int) – The block number within the entanglement layers.

  • num_block_qubits (int) – The number of qubits in the block.

Return type

List[List[int]]

Returns

The entangler map for the current block in the current repetition.

Raises

ValueError – If the value of entanglement could not be cast to a corresponding entangler map.