# Copyright 2021 Huawei Technologies Co., Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ============================================================================
"""y gate related decompose rule."""
from mindquantum.core import gates
from mindquantum.core.circuit import Circuit
from mindquantum.utils.type_value_check import _check_control_num, _check_input_type
[docs]def cy_decompose(gate: gates.YGate):
"""
Decompose controlled :class:`~.core.gates.YGate` gate.
Args:
gate (:class:`~.core.gates.YGate`): a :class:`~.core.gates.YGate` with one control qubits.
Returns:
List[:class:`~.core.circuit.Circuit`], all possible decompose solution.
Examples:
>>> from mindquantum.algorithm.compiler import cy_decompose
>>> from mindquantum.core.circuit import Circuit
>>> from mindquantum.core.gates import Y
>>> cy = Y.on(1, 0)
>>> origin_circ = Circuit() + cy
>>> decomposed_circ = cy_decompose(cy)[0]
>>> origin_circ
q0: ────■─────
┃
┏━┻━┓
q1: ──┨ Y ┠───
┗━━━┛
>>> decomposed_circ
q0: ───────────■───────────
┃
┏━━━━┓ ┏━┻━┓ ┏━━━┓
q1: ──┨ S† ┠─┨╺╋╸┠─┨ S ┠───
┗━━━━┛ ┗━━━┛ ┗━━━┛
"""
_check_input_type('gate', gates.YGate, gate)
_check_control_num(gate.ctrl_qubits, 1)
circuit = Circuit()
q0 = gate.ctrl_qubits[0]
q1 = gate.obj_qubits[0]
circuit += gates.S.on(q1).hermitian()
circuit += gates.X.on(q1, q0)
circuit += gates.S.on(q1)
return [circuit]
decompose_rules = ['cy_decompose']
__all__ = decompose_rules