ms_infidelity

ions.ms_infidelity(phases, displacements, target_phases, mean_phonon_numbers=None, *, name=None)

Calculate the final operational infidelity of the Mølmer–Sørensen gate.

This function calculates the operational infidelity with respect to the target phases that you specify in the target_phases array. It can use the tensors returned from ms_phases and ms_displacements to calculate the infidelity tensor.

Parameters:

phases (np.ndarray(real) or Tensor(real)) – The acquired phases between ion pairs, \(\{\Phi_{ln}\}\). Its shape must be (N, N) without time samples or (T, N, N) with them, where T is the number of samples and N is the number of ions. For each sample, the phases array must be a strictly lower triangular matrix.
displacements (np.ndarray(complex) or Tensor(complex)) – The motional displacements in phase-space, \(\{\eta_{jkl} \alpha_{jkl}\}\). Its shape must be (3, N, N_d) without time samples or (T, 3, N, N_d) with them, where the dimensions indicate, respectively, (time,) axis, collective mode, and ion. Here, N_d is the number of addressed ions.
target_phases (np.ndarray(real)) – The target total relative phases between ion pairs, \(\{\Psi_{ln}\}\), as a strictly lower triangular matrix of shape (N, N).
mean_phonon_numbers (np.ndarray or None, optional) – The mean phonon occupation of motional modes, \(\{\bar{n}_{jk}\}\). Its shape must be (3, N), where the dimensions indicate, respectively, axis and collective mode. If provided, must contain positive real numbers. If not provided, \(\bar{n}_{jk} = 0\), meaning no occupation of each mode.
name (str or None, optional) – The name of the node.

Returns:

A scalar or 1D tensor of infidelities with shape (T,).

Return type:

Tensor(real)