qml.qchem.qubit_observable¶
- qubit_observable(o_ferm, cutoff=1e-12, mapping='jordan_wigner')[source]¶
Convert a fermionic observable to a PennyLane qubit observable.
- Parameters
o_ferm (Union[FermiWord, FermiSentence]) – fermionic operator
cutoff (float) – cutoff value for discarding the negligible terms
mapping (str) – Specifies the fermion-to-qubit mapping. Input values can be
'jordan_wigner','parity'or'bravyi_kitaev'.
- Returns
Simplified PennyLane Hamiltonian
- Return type
Example
>>> w1 = qml.FermiWord({(0, 0) : '+', (1, 1) : '-'}) >>> w2 = qml.FermiWord({(0, 0) : '+', (1, 1) : '-'}) >>> s = qml.FermiSentence({w1 : 1.2, w2: 3.1}) >>> print(qubit_observable(s)) -0.775j * (Y(0) @ X(1)) + 0.775 * (Y(0) @ Y(1)) + 0.775 * (X(0) @ X(1)) + 0.775j * (X(0) @ Y(1))