- componentAn integer corresponding to the direction in order parameter space this kernel acts in (e.g. for unrotated functionals 0 for q_x, 1 for q_y, 2 for q_z).
C++ Type:unsigned int
Controllable:No
Description:An integer corresponding to the direction in order parameter space this kernel acts in (e.g. for unrotated functionals 0 for q_x, 1 for q_y, 2 for q_z).
- mag1_xThe x component of the constrained 1st sublattice magnetization vector
C++ Type:std::vector<VariableName>
Controllable:No
Description:The x component of the constrained 1st sublattice magnetization vector
- mag1_yThe y component of the constrained 1st sublattice magnetization vector
C++ Type:std::vector<VariableName>
Controllable:No
Description:The y component of the constrained 1st sublattice magnetization vector
- mag1_zThe z component of the constrained 1st sublattice magnetization vector
C++ Type:std::vector<VariableName>
Controllable:No
Description:The z component of the constrained 1st sublattice magnetization vector
- mag_subAn integer corresponding to the sublattice this Kernel acts on
C++ Type:unsigned int
Controllable:No
Description:An integer corresponding to the sublattice this Kernel acts on
- variableThe name of the variable that this residual object operates on
C++ Type:NonlinearVariableName
Controllable:No
Description:The name of the variable that this residual object operates on
AFMHomogeneousSublatticeExchange
Calculates a residual contribution for the sublattice exchange in an antiferromagnet
Overview
Computes the residual and jacobian entries from the LLG equation due to a free energy density, , corresponding to short-range sublattice exchange energy between two sublattice magnetizations in an antiferromagnet,
where and . Note that we do not use the conventional factor of 2 in these definitions but they can be evaluated after or during the simulation. Rewriting the above free energy, we have
The effective field due to this term can be calculated for each sublattice,
The effective field is evaluated at every time step of the two sublattice LLG-LLB equation,
(1)
where is the electron gyromagnetic factor and the phenomenological Gilbert damping parameter. Ignoring the time derivative, moving over the RHS to the LHS, and multiplying by a test function , we have
Substituting the expression for and writing the above in index notation gives the residual contribution for the component,
where (i.e. or vice versa). To calculate the on- and off-diagonal jacobian entries, we need,
where and correspond to the on- and off-diagonal jacobian contributions.
Example Input File Syntax
Input Parameters
- blockThe list of blocks (ids or names) that this object will be applied
C++ Type:std::vector<SubdomainName>
Controllable:No
Description:The list of blocks (ids or names) that this object will be applied
- displacementsThe displacements
C++ Type:std::vector<VariableName>
Controllable:No
Description:The displacements
- mag2_xThe x component of the constrained 2nd sublattice magnetization vector
C++ Type:std::vector<VariableName>
Controllable:No
Description:The x component of the constrained 2nd sublattice magnetization vector
- mag2_yThe y component of the constrained 2nd sublattice magnetization vector
C++ Type:std::vector<VariableName>
Controllable:No
Description:The y component of the constrained 2nd sublattice magnetization vector
- mag2_zThe z component of the constrained 2nd sublattice magnetization vector
C++ Type:std::vector<VariableName>
Controllable:No
Description:The z component of the constrained 2nd sublattice magnetization vector
- prop_getter_suffixAn optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.
C++ Type:MaterialPropertyName
Controllable:No
Description:An optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.
Optional Parameters
- absolute_value_vector_tagsThe tags for the vectors this residual object should fill with the absolute value of the residual contribution
C++ Type:std::vector<TagName>
Controllable:No
Description:The tags for the vectors this residual object should fill with the absolute value of the residual contribution
- extra_matrix_tagsThe extra tags for the matrices this Kernel should fill
C++ Type:std::vector<TagName>
Controllable:No
Description:The extra tags for the matrices this Kernel should fill
- extra_vector_tagsThe extra tags for the vectors this Kernel should fill
C++ Type:std::vector<TagName>
Controllable:No
Description:The extra tags for the vectors this Kernel should fill
- matrix_tagssystemThe tag for the matrices this Kernel should fill
Default:system
C++ Type:MultiMooseEnum
Controllable:No
Description:The tag for the matrices this Kernel should fill
- vector_tagsnontimeThe tag for the vectors this Kernel should fill
Default:nontime
C++ Type:MultiMooseEnum
Controllable:No
Description:The tag for the vectors this Kernel should fill
Tagging Parameters
- control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
- diag_save_inThe name of auxiliary variables to save this Kernel's diagonal Jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
C++ Type:std::vector<AuxVariableName>
Controllable:No
Description:The name of auxiliary variables to save this Kernel's diagonal Jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
- enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:Yes
Description:Set the enabled status of the MooseObject.
- implicitTrueDetermines whether this object is calculated using an implicit or explicit form
Default:True
C++ Type:bool
Controllable:No
Description:Determines whether this object is calculated using an implicit or explicit form
- save_inThe name of auxiliary variables to save this Kernel's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
C++ Type:std::vector<AuxVariableName>
Controllable:No
Description:The name of auxiliary variables to save this Kernel's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
- seed0The seed for the master random number generator
Default:0
C++ Type:unsigned int
Controllable:No
Description:The seed for the master random number generator
- use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.