Note

This page was generated from tut/quick-topics/Testing-QComponents-for-overlap-and-collisions.ipynb.

Demo Notebook Demonstrating How to Test for Component/CPW Overlap

⚠️ Deprecated — use ``qiskit_metal.validation`` instead

QDesignCheck prints its results and detects only crossing outlines, so it misses an overlap where one trace sits entirely inside another. It is also blind to layers (an airbridge over a CPW reports as a collision) and to intentional pin connections. Constructing it now emits a DeprecationWarning.

The replacement covers the same ground and returns structured findings:

from qiskit_metal.validation import validate

result = validate(design)
if not result:
    print(result.report())

See tutorial 2.24 Design rule checking for the full walkthrough.

💡 Using this tutorial without the Qt GUI

This tutorial uses the desktop MetalGUI. To follow along on Colab, Binder, JupyterHub, or any environment where Qt isn’t available, replace any ``gui.rebuild()`` / ``gui.screenshot()`` call with ``qm.view(design)`` — it renders the design to a matplotlib Figure you can display inline or save with fig.savefig(...).

See 1.1 Quick start for a complete runnable walkthrough and `docs/headless-usage.rst <../../docs/headless-usage.rst>`__ for the full reference.

This tutorial notebook demonstrates how to use the QDesign_Check class to test for overlap and/or collisions between componenets in a design. Let’s start by importing the relevant modules and opening up the GUI:

import qiskit_metal as metal
from qiskit_metal import designs, draw
from qiskit_metal import MetalGUI, Dict, open_docs
from qiskit_metal.qlibrary.qubits.transmon_pocket_6 import TransmonPocket6

design = metal.designs.DesignPlanar()
gui = metal.MetalGUI(design)
design.overwrite_enabled = True
design.chips.main

Design #1: CPW/Qubit Collision

Let’s create a design with three qubits in a straight line. Then we’ll connect the outer two qubits with a CPW which (intentionally) intersects the middle qubit.

Q1 = TransmonPocket6(
    design,
    "Q1",
    options=dict(
        pos_x="-2mm",
        pos_y="0mm",
        pad_width="425 um",
        pocket_height="650um",
        connection_pads=dict(
            readout=dict(loc_W=1, loc_H=-1, pad_width="100um", pad_gap="50um"),
            bus_01=dict(loc_W=1, loc_H=1, pad_width="100um", pad_gap="50um"),
        ),
    ),
)

Q2 = TransmonPocket6(
    design,
    "Q2",
    options=dict(
        pos_x="2mm",
        pos_y="0mm",
        orientation=0,
        pad_width="425 um",
        pocket_height="650um",
        connection_pads=dict(
            readout=dict(loc_W=-1, loc_H=-1, pad_width="100um", pad_gap="50um"),
            bus_01=dict(loc_W=-1, loc_H=1, pad_width="100um", pad_gap="50um"),
        ),
    ),
)

Q3 = TransmonPocket6(
    design,
    "Q3",
    options=dict(
        pos_x="0mm",
        pos_y="0mm",
        orientation=0,
        pad_width="425 um",
        pocket_height="650um",
        connection_pads=dict(
            readout=dict(loc_W=-1, loc_H=-1, pad_width="100um", pad_gap="50um"),
            bus_01=dict(loc_W=-1, loc_H=1, pad_width="100um", pad_gap="50um"),
        ),
    ),
)

gui.rebuild()
gui.autoscale()

from qiskit_metal.qlibrary.tlines.meandered import RouteMeander
from qiskit_metal.qlibrary.tlines.pathfinder import RoutePathfinder
from qiskit_metal.qlibrary.tlines.anchored_path import RouteAnchors
from qiskit_metal.qlibrary.tlines.straight_path import RouteStraight

bus1 = RoutePathfinder(
    design,
    "coupler1",
    Dict(
        pin_inputs=Dict(
            start_pin=Dict(component="Q1", pin="readout"),
            end_pin=Dict(component="Q2", pin="readout"),
        ),
    ),
)

gui.rebuild()
gui.autoscale()

Let’s look at a screenshot to see that there is in fact a CPW/qubit collision:

gui.screenshot()

Indeed we can see the CPW being routed straight through the middle qubit. We can use the “overlap_tester” function in the QDesign_Check class to verify that this is caught:

Let’s now import the QDesign_Check class, which contains several useful functions to test for overlap and collisions among design components:

from qiskit_metal.qlibrary.core.design_check import QDesignCheck

a_tester = QDesignCheck(design)

And now we’ll test the design for any overlap or collision errors:

a_tester.overlap_tester()

This function tells us that there is a collision between component 3 (the middle qubit) and component 4 (the CPW.)

Design #2: CPW/CPW Collision

Now let’s modify the existing design to create a scenario where two CPW resonators intersect with one another. We can do this by shifting the middle qubit up and adding another qubit below it:

Q3.options.pos_y = "2.0 mm"
Q3.options.orientation = "90"

Q4 = TransmonPocket6(
    design,
    "Q4",
    options=dict(
        pos_x="0mm",
        pos_y="-2mm",
        orientation=270,
        pad_width="425 um",
        pocket_height="650um",
        connection_pads=dict(
            readout=dict(loc_W=-1, loc_H=-1, pad_width="100um", pad_gap="50um"),
            bus_01=dict(loc_W=-1, loc_H=1, pad_width="100um", pad_gap="50um"),
        ),
    ),
)

gui.rebuild()
gui.autoscale()

from qiskit_metal.qlibrary.tlines.meandered import RouteMeander
from qiskit_metal.qlibrary.tlines.pathfinder import RoutePathfinder
from qiskit_metal.qlibrary.tlines.anchored_path import RouteAnchors
from qiskit_metal.qlibrary.tlines.straight_path import RouteStraight

bus1 = RouteStraight(
    design,
    "coupler2",
    Dict(
        pin_inputs=Dict(
            start_pin=Dict(component="Q3", pin="readout"),
            end_pin=Dict(component="Q4", pin="readout"),
        ),
    ),
)

gui.rebuild()
gui.autoscale()

gui.screenshot()

Indeed we can see that the two CPWs are crossing one another. Let’s see if the overlap_tester catches this:

a_tester.update_design(design)
a_tester.overlap_tester()

We see that the collision is detected between component 4 (the horizontal CPW) and component 5 (the vertical CPW).

Design #3: Qubit/Qubit Overlap

Let’s modify the existing design to remove the CPWs and move one of the qubits so that it’s partially overlapping with another:

design.delete_component("coupler1")
design.delete_component("coupler2")
Q4.options.pos_y = "1.5 mm"
gui.rebuild()
gui.autoscale()

gui.screenshot()

a_tester.update_design(design)
a_tester.overlap_tester()

Here we see that program correctly identified a collision between qubits 3 and 5.

For more information, review the Introduction to Quantum Computing and Quantum Hardware lectures below

Superconducting Qubits I: Quantizing a Harmonic Oscillator, Josephson Junctions Part 1	Lecture Video	Lecture Notes	Lab
Superconducting Qubits I: Quantizing a Harmonic Oscillator, Josephson Junctions Part 2	Lecture Video	Lecture Notes	Lab
Superconducting Qubits I: Quantizing a Harmonic Oscillator, Josephson Junctions Part 3	Lecture Video	Lecture Notes	Lab
Superconducting Qubits II: Circuit Quantum Electrodynamics, Readout and Calibration Methods Part 1	Lecture Video	Lecture Notes	Lab
Superconducting Qubits II: Circuit Quantum Electrodynamics, Readout and Calibration Methods Part 2	Lecture Video	Lecture Notes	Lab
Superconducting Qubits II: Circuit Quantum Electrodynamics, Readout and Calibration Methods Part 3	Lecture Video	Lecture Notes	Lab