Periodic Condition
The Periodic Condition allows modeling just one unit cell of a periodic structure, such as superlattices.
Boundary Selection
The software usually automatically identifies the boundaries as either source boundaries or destination boundaries, as indicated in the selection list. This works fine for cases like opposing parallel boundaries. In other cases, right-click Periodic Condition and select Manual Destination Selection to control the destination. By default it contains the selection that COMSOL Multiphysics identifies.
Destination Selection
This section is available for specifying the destination boundaries, if needed, when the Manual Destination Selection option is selected in the context menu for the Periodic Condition node. You can only select destination boundaries from the union of all source and destination boundaries.
Periodicity Settings
Select an option from the Type of periodicity list: Continuity (the default) or Floquet–Bloch periodicity.
For Floquet–Bloch periodicity, enter the k-vector for Floquet periodicity kF (rad/m). The default is the null vector, reducing the condition to be equivalent to Continuity. For time dependent studies, the Floquet–Bloch periodicity option does not apply. If erroneously selected, it will be reduced to the continuity condition.
Constraint Settings
To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog box. For information about the Constraint Settings section, see Constraint Settings in the COMSOL Multiphysics Reference Manual.
Orientation of Source
To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog box. For information about the Orientation of Source section, see Orientation of Source and Destination in the COMSOL Multiphysics Reference Manual.
Orientation of Destination
This section appears if the setting for Transform to intermediate map in the Orientation of Source section is changed from the default value, Automatic, and Advanced Physics Options is selected in the Show More Options dialog box. For information about the Orientation of Destination section, see Orientation of Source and Destination in the COMSOL Multiphysics Reference Manual.
Mapping Between Source and Destination
To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog box. For information about the Mapping Between Source and Destination section, see Mapping Between Source and Destination in the COMSOL Multiphysics Reference Manual.