KQCircuits objects, such as elements and chips, can be viewed and manipulated in the KLayout Editor GUI. More complicated tasks in KLayout Editor can be done by writing KLayout macros, which use the KQCircuits library. The code runs within KLayout’s built-in Python interpreter, so debugging must be done in KLayout’s macro IDE if using KLayout GUI. Note that the macros can also be run from the command line without GUI (-z and -r) switches, which allows using other debugging tools.

To use KQC in KLayout, open KLayout in editing mode (go to File->Setup->Application->Editing mode, check use editing mode by default and restart, or launch KLayout(Editor) application if on Windows). If KQC was installed successfully, you should then see KQC libraries such as Element library and Chip library in KLayout’s library browser. The elements can then be dragged and dropped from there to the layout. The parameters of an element in the layout can be changed by double-clicking it. For more detailed instructions, see the User Guide.

Modifying or Creating Elements or Chips

KLayout Salt packages are read-only. The user may open a chosen chip (say, [Package KQCircuits]/kqcircuits/chips/simple) with the embedded macro editor (F5) but it can not be directly changed here. Of course, external code editors may be used to change these files or their copies. On the downside, package upgrades may override these changes.

An other option is to copy (drag-and-drop) the Simple chip to the [Local] folder with the embedded macro editor. This copy may be freely changed with the macro editor. First suggested change would be to rename the chip. This is still not part of KQC. To make it visible in KLayout we need to create a symbolic link to it from the designated chip folder in [Package KQCircuits]/kqcircuits/chips/. Finally, KLayout should re-read the now update KQC library, this may be achieved by restarting or with the Edit -> KQCircuits Library -> Reload libraries menu entry.

It may take a bit of effort to find where these folders are in a particular OS, in Linux:

cd $HOME/.klayout/salt/KQCircuits/python/kqcircuits/chips
ln -s $HOME/.klayout/pymacros/

or in Windows:

cd %HOME%/KLayout/salt/KQCircuits/python/kqcircuits/chips
mklink "%HOME%/KLayout/pymacros/"

Naturally, the same approach would work to copy/create other elements, qubits etc. Creating macros or masks is even easier, no need to fumble with external editors or symlinks the default [Local] folder may be directly used to run the copied and modified macro or mask generation script. But for serious development work we suggest following the Developer Setup.