commutator¶

commutator(op_a, op_b)¶

Computes the commutator of two operators.

The commutator is defined as:

\[[A, B] = AB - BA\]

Operators which support this method must implement the SupportsCommutators protocol.

Note

Both inputs must be of the same operator type. This will also determine the output type.

>>> from qiskit_fermions.operators import FermionOperator
>>> from qiskit_fermions.operators.library import commutator
>>> op1 = FermionOperator.from_dict({((True, 0), (False, 0)): 1})
>>> op2 = FermionOperator.from_dict({((False, 0), (True, 0)): 2})
>>> comm = commutator(op1, op2)
>>> comm = comm.normal_ordered()
>>> canon = comm.simplify()
>>> assert canon == FermionOperator.zero()

Parameters:

op_a (SupportsCommutators) – the operator \(A\) above.
op_b (SupportsCommutators) – the operator \(B\) above.

Returns:

The commutator \([A, B]\).

Return type:

SupportsCommutators