obtain_ion_chain_properties

boulderopal.ions.obtain_ion_chain_properties(atomic_mass, ion_count, center_of_mass_frequencies, wavevector, laser_detuning=None)

Calculate the Lamb–Dicke parameters, frequencies (or relative detunings if a laser detuning is provided), and eigenvectors of the collective motional modes of an ion chain.

Parameters:
  • atomic_mass (float) – The atomic mass of the ions of the chain in atomic units. All ions in the chain are assumed to be of the same species.

  • ion_count (int) – The number of ions in the chain, \(N\).

  • center_of_mass_frequencies (np.ndarray) – The center-of-mass trapping frequencies in each direction. Must contain three positive elements.

  • wavevector (np.ndarray) – The laser difference angular wave vector (in rad/m) in each direction. Must contain three elements.

  • laser_detuning (float or None, optional) – The detuning of the control laser. If not provided, the returned relative detunings represent the mode frequencies.

Returns:

A dictionary containing the ion chain properties, with the following keys:

lamb_dicke_parameters

A 3D array of shape (3, N, N) representing the Lamb–Dicke parameters of the ions. Its dimensions indicate, respectively, direction, mode, and ion.

relative_detunings

A 2D array of shape (3, N) representing the mode frequencies (or relative detunings if a laser detuning is provided). Its dimensions indicate, respectively, direction and mode.

eigenvectors

A 3D array of shape (3, N, N) representing the eigenvectors of each mode. Its dimensions indicate, respectively, direction, mode, and ion.

metadata

Metadata associated with the calculation. No guarantees are made about the contents of this metadata dictionary; the contained information is intended purely to help interpret the results of the calculation on a one-off basis.

Return type:

dict

See also

boulderopal.ions.ms_optimize

Find optimal pulses to perform Mølmer–Sørensen-type operations on trapped ions systems.

boulderopal.ions.ms_simulate

Simulate a Mølmer–Sørensen-type operation on a trapped ions system.

Notes

The directions of input parameters and returned arrays are ordered as radial x-direction, radial y-direction, and axial z-direction, corresponding, respectively, to the unit vectors \((1, 0, 0)\), \((0, 1, 0)\), and \((0, 0, 1)\).

Examples

Refer to the How to optimize error-robust Mølmer–Sørensen gates for trapped ions user guide to find how to use this function.