mindquantum.algorithm.compiler.cu_decompose

mindquantum.algorithm.compiler.cu_decompose(gate: QuantumGate, with_barrier: bool = False)[source]

Decompose arbitrary-dimension controlled-U gate.

This gate has \(m\) control qubits and \(n\) target qubits. When recursively calling the function itself, \(m\) decreases, while \(n\) holds constant.

Parameters

gate (QuantumGate) – instance of quantum gate.
with_barrier (bool) – whether add BarrierGate into decomposed circuit. Default: False.

Returns

Circuit, composed of 1-qubit gates and CNOT gates.

Examples

>>> import mindquantum as mq
>>> from mindquantum.algorithm.compiler import cu_decompose
>>> from scipy.stats import unitary_group
>>> cqs = [0, 2, 4, 5]
>>> tqs = [1, 6]
>>> m = len(cqs)
>>> n = len(tqs)
>>> u = unitary_group.rvs(2 ** n, random_state=123)
>>> g = mq.UnivMathGate('U', u).on(tqs, cqs)
>>> circ = cu_decompose(g)
>>> num_cnot = len([g for g in circ if isinstance(g, mq.XGate) and len(g.ctrl_qubits)==1])
>>> print('total gate number: {}, CNOT number: {}'.format(len(circ), num_cnot))
total gate number: 632, CNOT number: 314