rotating_frame_operator

Model.rotating_frame_operator(t, only_diag=False, in_qubit_subspace=False, inverse=False)

Return the rotating-frame operator defined by rotating_frame_hamiltonian.

By default (rotating_frame_hamiltonian='local_qubit_z'),

\[U_\text{rot}(t) = \bigotimes_{i\in\text{spins}} e^{i 2 \pi f_i t \sigma_{z,i}/2},\]

where \(f_i\) are the rotating frame frequencies of the spins and \(\sigma_{z,i}\) are the Pauli z-operators. Frequencies are specified in the BaseSpin.rotating_frame_frequency attribute.

If rotating_frame_hamiltonian is 'static_hamiltonian' or a square matrix, that matrix is interpreted as a rotating-frame Hamiltonian \(H_\mathrm{rf}\) and the operator is

\[U_\text{rot}(t) = e^{-i 2 \pi t H_\mathrm{rf}}.\]
Parameters:

  • t (float | List[float] | ndarray | Array) – Time point(s).

  • only_diag (bool) – If True, return only the diagonal of the operator.

  • in_qubit_subspace (bool) – If True, return the operator represented in the qubit subspace.

  • inverse (bool) – If True, return the inverse of the operator.

Return type:

ndarray | Array

Returns:

Rotating-frame operator(s). Shape depends on the only_diag parameter and the type of t.