dnp_field_scan.m

Magnetic field scan steady-state DNP experiment. Returns the steady-state population of the user-specified state as a function of magnetic field.

Syntax

dnp=dnp_field_scan(spin_system,parameters,H,R,K)

Arguments

parameters.mw_pwr - microwave power, Hz

    parameters.mw_frq      -   microwave frequency offset from 
                               the free electron frequency at 
                               the reference B0 field, Hz

    parameters.fields      -   a vector of magnetic field off-
                               sets from the reference B0 field,
                               Tesla

    parameters.rho0        -   equilibrium state at the reference
                               B0 field

    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 matrix, received from context function

    R - relaxation superoperator, received from context function

    K - kinetics superoperator, received from context function

Outputs

dnp - an array of steady state expectation values for

             the states specified in parameters.coil at each
             of the fields supplied

Note: the relaxation superoperator should NOT be thermalized
      for this type of calculation.

Note: thermal equilibrium state and relaxation superoperator are
      assumed to be the same at all fields in the sweep - DO NOT
      USE with broad magnetic field sweep experiments.

ilya.kuprov@weizmann.ac.il

Examples

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

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):

Notes

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.

See also

DNP experiments

Version 2.5, authors: Ilya Kuprov, Walter Kockenberger, Alexander Karabanov, Maria Grazia Concilio

Returns

dnp - an array of the steady state amplitudes of the

              states specified in parameters.coil as at each
              of the magnetic fields supplied