Adding a Junction

[Diego-planckian1]

Hi,

I'm having some troubles in the insertion of my own junction.

I created a junction geometry and place the .py in the junctions folder. I can see it in the GUI of klayout (Planck SQUID):

By the way once i try to add it inside an other script (for generating a qubit) it print me the default Manhattan junction. How I can I add my own junction?

This is the dummy code I implemented:

Where PlanckSQUID is the class of my junction.

[Qvadi]

I think the problem here is a bit of naming culture in KQCircuits. Normally the import structure is as follows:
For example, my_element.py (a file under the kqcircuits\elements folder) is something that the user creates, then your import structure you need to follow is this:
from kqcircuits.elements.my_element import MyElement

Note: the character after the 'underscore' is capitalized.
In your case, the faulty line of code is the planck_junction import. The correct way to import this file is,
from kqcircuits.junctions.planck_junction import PlanckJunction

If this is not the right file, then adjust it accordingly.

[Diego-planckian1]

To avoid misunderstandings I changed the names:

Still print the manhattan squid...

[Diego-planckian1]

Also if I use one of the default junction in my script (e.g. manhattan single junction), in the output i still have the default manhattan junction!

[Qvadi]

There is still a typo in your code, should be PlanckTransmonCap. Not sure what else could be wrong.

[Diego-planckian1]

PlanckTransmonCap is an element, the capacitance of the transmon, and it is inserted correctly. The problem regards the insertion of a junction.:

I tried to insert my own junction --> give me back the default manhattan junction.

I substituted PlanckJunction with ManhattanSingleJunction ---> again the default Manhattan SQUID.

What could be mistaken? I don't know i the junction adding follows the same rule of the element adding.

[nikosavola]

You can try checking the example in https://github.com/iqm-finland/KQCircuits/blob/main/klayout_package/python/kqcircuits/qubits/swissmon.py. Seems the junction is a special case implemented in the Qubit class. You should use self.produce_squid for placing the junction. This way the PCell parameter for junction type is obeyed.

[qpavsmi]

Maybe this can help (sorry for the delay)

Go to klayout_package/python/kqcircuits/junctions/__init__.py. There is a dict called junction_type_choices with a list of junctions that can be placed in the qubit. These are given as an option when you want to edit the junction_type of a qubit of your choice. Try adding your squid as an entry, it should be a string as shown in GUI, either "Planck SQUID" or "Planck Junction".

Then check out Niko's comment, you should call produce_squid with transformation as argument that tells at which coordinate and orientation your squid is placed at. Now try drag-and-dropping your qubit to the layout, and change the parameter junction_type from the parameters. Might have to click the option two times because this part of gui is a bit buggy :/ Let me know if you'll see your squid on a qubit with this