tequila.hamiltonian.paulis.KetBra

tequila.hamiltonian.paulis.KetBra(ket: tequila.wavefunction.qubit_wavefunction.QubitWaveFunction, bra: tequila.wavefunction.qubit_wavefunction.QubitWaveFunction, hermitian: bool = False, threshold: float = 1e-06, n_qubits=None)[source]

Initialize the general KetBra operator

Notes

Initialize the general KetBra operator

\[H = \lvert ket \rangle \langle bra \rvert\]

e.g.

>>> wfn1 = tq.QubitWaveFunction.from_string("1.0*|00> + 1.0*|11>").normalize()
>>> wfn2 = tq.QubitWaveFunction.from_string("1.0*|00>")
>>> operator = tq.paulis.KetBra(ket=wfn1, bra=wfn1)

initializes the transfer operator from the all-zero state to a Bell state

Parameters

  • ket (QubitWaveFunction) – QubitWaveFunction which defines the ket element can also be given as string or array or integer

  • bra (QubitWaveFunction) – QubitWaveFunction which defines the bra element can also be given as string or array or integer

  • hermitian (bool (Default False)) – if True the hermitian version H + H^dagger is returned

  • threshold (float (Default 1.e-6)) – elements smaller than the threshold will be ignored

  • n_qubits (only needed if ket and/or bra are passed down as integers) –

Returns

a tequila QubitHamiltonian (not necessarily hermitian) representing the KetBra operator desired.

Return type

QubitHamiltonian