Dnp field scan.m

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Magnetic field scan steady-state DNP experiment.


Returns the steady-state population of the user-specified state as a function of magnetic field.



This function should normally be called via powder.m or crystal.m wrapper.


    parameters.mw_pwr      -   microwave power, Hz

    parameters.mw_frq      -   microwave frequency, Hz

    parameters.fields      -   a vector of B0 field values, T

    parameters.rho_eq      -   thermal equilibrium state

    parameters.coil        -   detection state vector or a horizon-
                               tal stack thereof

    parameters.mw_oper     -   microwave irradiation operator

    parameters.ez_oper     -   Lz operator on the electrons

    parameters.method      -   'backslash' to use Matlab's
                               linear equation solver, 'gmres'
                               to use ILU preconditioned GMRES

    H                      -   Hamiltonian commutation superoperator

    R                      -   unthermalised relaxation superoperator 

    K                      -   chemical kinetics superoperator


    answer                 -   the projection of the equilibrium density matrix 
                               on the user-specified state as a function of the
                               applied magnetic field


Cross effect in a system with two spin-1/2 electrons (cross_effect_field_scan_1.m example file in examples/dnp_solids directory):

Dnp example 1.png

Solid effect in a system with a spin-7/2 gadolinium ion (solid_effect_field_scan_1.m example file in examples/dnp_solids directory):

Dnp example 2.png


  1. The relaxation superoperator supplied to this function should NOT be thermalized.
  2. Thermal equilibrium state is assumed to be the same at all fields in the sweep. Do not use this function for broad magnetic field sweep experiments.
  3. Backslash method is recommended for small spin systems and GMRES method for large ones.
  4. This function can be made to run on GPUs. If you would like that functionality added, send an email to Ilya Kuprov.

See also

dnp_freq_scan.m, masdnp.m, solid_effect.m

Revision 3284, authors: Ilya Kuprov, Walter Kockenberger, Alexander Karabanov