Intrep.m

Interaction representation transformation with respect to a specified Hamiltonian to specified order in perturbation theory (https://doi.org/10.1063/1.4928978).

Syntax

   Hr=intrep(spin_system,H0,H,T,order)

Parameters

   H0     - the Hamiltonian with respect to which the
            interaction representation transformation
            is to be done, typically Zeeman Hamiltonian

   H      - laboratory frame Hamiltonian H0+H1 that is
            to be transformed into the interaction rep-
            resentation, typically the full Hamiltonian

   T      - period of the H0 propagator

   order  - perturbation theory order in the rotating
            frame transformation, this may be inf

Outputs

   Hr     - Hamiltonian in the interaction representation

Examples

See 14N quadrupolar NMR examples (examples/nmr_solids/rframe_nqi_*.m) where the quadrupolar shift is a second order perturbation theory property.

Notes

This module is called by context functions when the user specifies a numerical rotating frame transformation. It is generally a good idea to do this when your interactions are not much smaller than the Zeeman Hamiltonian, but you are not willing to run the calculation in the laboratory frame.

See also

dirdiff.m, expmint.m, average.m

Version 2.2, authors: Ilya Kuprov, David Goodwin