Source code for pennylane.ops.functions.is_hermitian
# Copyright 2018-2021 Xanadu Quantum Technologies Inc.# 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."""This module contains the qml.is_hermitian function."""importpennylaneasqmlfrompennylane.operationimportOperator
[docs]defis_hermitian(op:Operator):r"""Check if the operation is hermitian. A hermitian matrix is a complex square matrix that is equal to its own adjoint .. math:: O^\dagger = O Args: op (~.operation.Operator): the operator to check against Returns: bool: True if the operation is hermitian, False otherwise .. note:: This check might be expensive for large operators. **Example** >>> op = qml.X(0) >>> qml.is_hermitian(op) True >>> op2 = qml.RX(0.54, wires=0) >>> qml.is_hermitian(op2) False """ifop.is_hermitianisTrue:returnTruereturnqml.math.allclose(qml.matrix(op),qml.matrix(qml.adjoint(op)))