current through hole

[Damm22]

After running my simulations I realized, that there is some current runnigng through the hole.

Is it possible to remove the mesh inside the hole?
I am having trouble calculating the Inductance of my devices. While I can easily calculate the inductance, the result is heavily dependent on the mesh size.

[loganbvh]

No, it is not possible to remove the mesh inside the hole in SuperScreen. How are you calculating the inductance? Can you share a more detailed example?

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On Thu, Jan 16, 2025 at 8:25 AM Damm22 ***@***.***> wrote: After running my simulations I realized, that there is some current runnigng through the hole. cantilever_simulation_ausschneiden.-.Kopie.png (view on web) <https://github.com/user-attachments/assets/dfdc85d7-e03d-46cc-91b3-7c51d36999c4> Is it possible to remove the mesh inside the hole? I am having trouble calculating the Inductance of my devices. While I can easily calculate the inductance, the result is heavily dependent on the mesh size. — Reply to this email directly, view it on GitHub <#118>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AE3CFETCZUS67X5FTFEGNB32K6XLZAVCNFSM6AAAAABVJTU3HWVHI2DSMVQWIX3LMV43ASLTON2WKOZSG44TENZXGIZTKMA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[Damm22]

this is what my device looks like:

and this is how I simulate and calculate the Inductance

applied_field = sc.sources.ConstantField(B * c.mu_0 * 1e9)
terminal_currents = {"squid": {"source": f"0 mA", "drain": f"-0 mA"}}
solutions = sc.solve(
                    device=device,
                    terminal_currents=terminal_currents,
                    circulating_currents={'hole': 1},
                    applied_field=applied_field,
                    field_units="uT",
                    current_units="mA",
                )
solution = solutions[-1]

I_circ = solution.circulating_currents["hole"] * device.ureg(solution.current_units)
fluxoid = solution.hole_fluxoid("hole")
L = (sum(fluxoid) / I_circ).to("Phi_0 / A")

however when I use different grid sizes I get different results:

(the different colors stand for different hole sizes [nm])

I dont get such weird results with other devices. (I tried a ring, a ring with two constriction junctions and even a triagle with two constriction junctions)

[loganbvh]

Can you try using device.mutual_inductance_matrix() to calculate the inductance (example here).

I would also suggest simulating a much smaller region of the device (just near the hole, for example y > -300 nm) with a finer mesh to get the hole inductance. The big leads will not change the self-inductance of the hole.